Evaluation of High-Occupancy Vehicle Priority Treatment ......Evaluation of High-Occupancy Vehicle...

TECHNICAL REPORT STANDARD TITLE PAGE

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FHWA/TX-85/30+339-1 !--,--:::c-:--------------.---.L-----------------------+.".-..,,-------.-... _ .................... .

4. Title and Subtitl.· 5. Report Date

Evaluation of Hiqh-Occupancy Vehicle Priority Treat- March 1984 ment Projects, (Study Pl an and Initi al 6:"'Month Pre- T-Per/orming Organization Cod;' ---.. -.

1 i minary Analysis) t---y:-A-u-th-orl-s)---" .-------.-------------.-------.- --.- a: -p-,,,-'o'r-,ni-ng O'gonl1.otion R;;;;-H N-" ----

Nana M. Kuo and John M. Mounce Research Report 339-1 ~--------.----------------------.----.----~~~~--~----------------~ 9. Performing Organization Name and Add,e.. 10. Work Unit No.

Texas Transportation Institute The Texas A&M University System College Station, Texas 77843

--------------------------~ 12. Sponsoring Agency Name and Address

11. Contract or Grant No.

Study No. 2-10-84-339 13. Type 0'1 Report and Period Cove,ed

Interim _ September 1983 March 1984 Texas State Department of Highways and Public

Transportation; Transportation Pl~nning Division P. O. Box 5051

~--::---------'-'----I 14. Sponso,ing Agency Code

Austi n. Texas 78'-'-7",.6.""3-c-_____________ ...J..-____________ -I 15. Supplementary Note.

Research performed in cooperation with DOT, FHWA. Research Study Title: Improving Urban Mobility Through Application of High-Occupancy Vehicle Priority Treatments.

16. Abstract

This report presents the study plan for the evaluation of three high occupancy vehicle facilities currently being developed in Houston, Texas. Preliminary analyses of data from the first six months of the study are presented. These data include park-and-ride demands, travel times and vehicle and person demands for the three freeway corridors studied.

Operational data will continue to be collected within the study corridors both monthly and quarterly throughout the evaluation period (five years).

17. Key Wards

High-Occupancy Vehicle Priority Treatments.

18. Distribution Statement No restriction. This document is available to the public through the National Technical Information Service, 5285 Port Royal Road, Springfield, Virginia 22161.

19. Security Classi!. (01 this ,epo,t) 20. Security Classi!. (01 thi. pagel 21. No. of Pages 22. Price

Unclassified Unclassified 60

Form DOT F 1700.7 (e-691

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Evaluation of High-Occupancy Vehicle Priority Treatment Projects

(Study Plan and Initial 6-Month Preliminary Analysis)

Prepared by

Nana M. Kuo Engineering Research Associate

and

John M. Mounce Associate Research Engineer

Research Report 339-1

Improving Urban Mobility Through Application of High-Occupancy Vehicle Priority Treatments

Research Study Number 2-10-84-339

Sponsored by

State Department of Highways and Public Transportation in Cooperation with the

U.S. Department of Transportation Federal Highway Administration

Texas Transportation Institute The Texas A&M University System

College Station, Texas

March 1984

ABSTRACT

This report presents the study plan for the evaluation of three high

occupancy vehic le faci 1 ities current ly being developed in Houston, Texas.

Preliminary analyses of data from the first six months of the study are

presented. These data include park-and-ride demands, travel times and

vehicle and person demands for the three freeway corridors studied.

Operational data will continue to be collected within the study

corridors both monthly and quarterly throughout the evaluation period (five

years).

SUfIo1ARY

The State Department of Highways and Public Transportation has strongly

endorsed provision for high-occupancy vehicle (HOV) priority treatment. The

first effort in this regard, the Houston Contraflow Lane (CFL), has proven

high ly successfu 1 from both an operationa 1 and a pub 1 ic acceptance stand

point. Subsequent projects, directed to exclusive, physically separated HOV

facilities, have reached implementation stage, and additional projects are in

the planning stage. However, many of the effects of priority treatment are

re 1 at i ve ly unknown. There have been few successfu 1 priority treatment pro

jects implemented nationwide; none of this type have previously been imple

mented in Texas. Therefore, it is very important to document and analyze

information from the deve lopment of these initia 1 HOV priority treatment

projects such as those on the Katy (I-lOW), North (I-45N) and Gulf (1-455)

Freeways in Houston, Texas.

In June 1983, two of the three study corridors a lready had transitway

construction work underway, and the third had preconstruction work underway.

The Gu lf Freeway transitway construct ion began as ear ly as September 1982.

i i

.~---------------~

The Katy Freeway had its construction ground breaking ceremonies in May 1983.

The North Freeway preconstruction preparatory work began in Apri 1 1983, but

actual construction did not begin until January 1984.

Consequently no comparative before and after analyses may be made at the

time of this report. Pre1 iminary findings from the first six months of data

collection and analysis are presented along with projections of the opera

tional effects of the implementation of a transitway. Use by high occupancy

vehicles (HOVs) and corresponding passenger throughput in HOVs is expected to

increase to 400 vehicles and 6,500 passengers. Likewise, the percentage of

total peak period passenger demand served by HOVs will increase from about 5%

to 35%. It is not known whether the extent of modal shift to the transitway

from the freeway main1anes will be significant enough to dramatically enhance

freeway operations, as this may possibly be negated by population growth,

latent demand, and diversion of traffic. However, this effect, if present,

wi 11 be noted.

Operational data will continue to be collected within the study corri

dors monthly and quarterly throughout the five year evaluation period. Up

dates for each freeway will be available as required.

iii

IMPLEMENTATION STATEMENT

This project was established to provide continued support to the Texas

State Department of Highways and Public Transportation for the implementation

of priority treatment techniques for high-occupancy vehicles. Several high

way-transit projects have been designed and are under construction, while

numerous others are in the conceptual and planning stages. This report

documents the first six months of a "before and after" evaluation of those

projects currently under implementation. The results of the subsequent

analysis will be summarized as guidelines for future projects.

DISCLAIMER

The contents of thi s report refl ect the views of the authors who are

responsible for the opinions, findings, and conclusions presented herein.

The contents do not necessarily reflect the official views or policies of the

Federal Highway Administration or the Texas State Department of Highways and

Publ ic Transportation. This report does not constitute a standard, specifi

cation, or regulation.

iv

TABLE OF CONTENTS

Abstract ................................................................ Surrmary

Implementation Statement

Disclaimer .............................................................. Introduction ............................................................

.............................................................. Scope Objectives .........................................................

Projects Under Implementation

Katy Freeway Transitway North Freeway Transitway Gulf Freeway Transitway

............................................

............................................ Study Design

Data Base .......................................................... Collection Methodology Analysis Techniques ................................................

Preliminary Results

Overview Park-and-Ride Parking Demand Travel Time/Speeds Contraflow Lane Transition Vehicle and Person Volumes .........................................

Summary

Projection of Findings ............................................. References

v

i i

i i

iv

iv

1

1 2

2

3 6 8

11

11 11 16

21

21 22 22 41 43

49

49

51

FIGURES

S-1. Katy Freeway Morning Operational Parameter Projections ••••••••.••••• iv

1. Scope of Transitway Projects Under Implementation ••••••••••••••.•••• 4

2. Katy Freeway Transitway, Phase Construction ••••••••••••••••••••••••• 5

3. North Freeway Transitway, Phase Construction •.••••••••.•..•.•••••••• 7

4. Gulf Freeway Transitway, Phase Construction •••••••••••••••.••••••.•• 9

5. Park-and-Ride Lot Locations ............•.•••......................•• 11

6. Park-and-Ride Demands In Study Corridors ••••...••••••••••••••••••••• 21

7. Gulf Freeway Total Travel Times ••.•.••.•.•••.••••••.•••••••••••.•••• 22

8. Gulf Freeway Overall Travel Speeds .•••.•.•.••••••••••••••••••••••••• 24

9. Gulf Freeway Peak Period Section Travel Speeds •••••••••.••••.••••••• 25

10. Gulf Freeway Peak Hour Section Travel Speeds .••.•••••••..••.•••••••• 26

11. Katy Freeway 1982-1983 Peak Hour Total Travel Times ••.•••..•..•••••• 28

12. Katy Freeway 1982-1983 Peak Hour Overall Travel Speeds ..••••••••••.• 29

13. Katy Freeway Total Travel Times •.•..••••.•••••••••••••••••.••••.•••• 30

14. Katy Freeway Overall Travel Speeds •.•••••••••••••••••••••.••.••.•••• 32

15. Katy Freeway Peak Period Section Travel Speeds .•.••••••..••.•••.•••• 33

16. Katy Freeway Peak Hour Section Travel Speeds •••••••••••••••••••••••• 34

17. North Freeway Total Travel Times •••••••••••••••••••••••••.•••••..••. 36

18. North Freeway Overall Travel Speeds .••.••.••.•.••.•••••••••••••••••. 37

19. North Freeway Peak Period Section Travel Speeds ••.•.••••••••••••••.• 38

20. North Freeway Peak Hour Section Travel Speeds ••••••••.•••••••••••••• 40

TABLES

1. Travel Time Check Points ••••••••••••••.•.••••••••••••••••••••••••••• 13

2. Vehicle and Occupancy Categories ••••••••••••.•....•..•••••••.•...••. 15

3. Travel Time Variables ••••••••••••••.•.•..••••••••••••••••••••••••••• 17

vi

INTRODUCTION

Scope

The tremendous growth experienced in urban areas of Texas in the 1 ast

decade has caused concern by state and 1 oca 1 transportation officia 1 s over

degradation of mobil ity. Future growth and economic vital ity in the Texas

metropol itan regions are in serious jeopardy unl ess major improvements are

implemented in the existing urban transportation system. It is clear that it

would be neither economically nor physically possible to provide enough

additional highway capacity (by expanding freeway cross-sections or by ex

panding transit services) to equal anticipated demand. Therefore, new and

innovative means of freeway system management have been looked to as possible

remedies.

One approach taken to increase capacity which is strongly endorsed by

both the State Department of Highways and Public Transportation and the

Metropol itan Transit Authority in Houston is to provide for high-occupancy

vehicle (HOV) priority treatment. The first effort, the. Houston Contraflow

Lane (CFL), has proven operationally successful and has received publ ic

acceptance. Several subsequent projects, exclusive, physically separated

authorized HOV facilities, have reached the implementation stage and numerous

additional projects are in the planning stage. However, many of the effects

of priority treatment are relatively unknown. There have been few successful

projects implemented nationwide; none of this type has previously been imple

mented in Texas. Therefore, it is important to document and analyze informa

tion from the implementation of these initial HOV priority treatment pro

jects.

Implementation of three projects on the Katy (I-lOW), North (I-45N), and

Gulf (I-45S) freeways in Houston, Texas will begin in 1984 and will continue

1

through 1987. It is the purpose of this report to present the evaluation

p1 an of these three projects and the pre1 iminary findings from the the six

months of data collection and analysis.

Objectives

The objectives of this study report are as follows:

1) Formulate a detailed study design for data collection and analysis of HOV projects;

2) Collect continuous operational data before, during, and after project implementation;

3) Monitor all activities during implementation of HOV projects with particular emphasis on the transition of the contraf10w lane to an

'exclusive, physically separated facility;

4) Perform a comprehensive evaluation of the implementation of each specified HOV project; and

5) Develop guide1 ines for app1 ication to future HOV projects.

PROJECTS UNDER IMPLEMENTATION

Houston, Texas is currently in the process of implementing exclusive,

physically separated HOV priority facilities (transitways) along three major

radial freeway corridors:

• Katy Freeway (I-lOW)

• North Freeway (I-45N)

• Gulf Freeway (I-45S)

The Katy, North and Gulf Transitways have similar designs with a tran-

sitway cross section of approximately 20 feet. They are single reversible

lanes; traffic will travel inbound toward downtown in the morning and out

bound in the afternoon. They are constructed within the existing median of

the freeway and protected from other traffic lanes by concrete barriers.

2

Adequate space is provided for emergencies and breakdowns within the transit

way. Access points are 1 imited and controlled. However, each transitway

facility differs slightly from the others in design, construction, and opera

tional features.

Geographical location and project 1 imits are illustrated in Figure 1.

Discussions of individual freeway corridors follow.

Katy Freeway Transitway

The Katy Freeway is a major interstate highway serving travel demands

from western Harris County to various parts of Houston. Traffic volumes have

increased at annua 1 rates in excess of 4% throughout the 1970's. Currently,

weekday traffic volumes approach 25,000 vehicles per lane; peak-direction

flow exceeds 1,900 vehicles per hour per 1ane.(1)

The Katy Freeway Transitway will be built and operated in three phases

(Figure 2). The first phase is being developed at this time and will stretch

five miles from Post Oak (near 1-610) to Gessner. The second phase will

extend the trans i tway another fi ve mi 1 es to SH 6 and the th i rd phase wi 11

include an interchange at Addicks. When fully completed, the transitway will

extend 11.5 mi 1 es from near the West Loop to Addicks and have intermediate

access at Gessner. Construction on the first phase began in April 1983 and

will be completed in October 1984.

At the eastern end near 1-610, a bridge over the freeway will connect

the transitway to Katy Road at the Post Oak intersection. From this inter

section, transitway traffic can turn north or south to reach major employment

centers along the West Loop, or continue eastward on 1-10 to downtown. At

Gessner, a ramp will provide direct access to and from the freeway main1anes,

and additional ramps will eventually be located at the western end at

Addicks.

3

North Belt

KATY 1-10E

10.0 Miles

1-610

Almeda - Genoa

LEGEND

___ Committed 40 mile.

Figure 1: Scope of Transitway Projects Under Implementation

4

fI)

~ c co Jl

CD .. «1

>0- u. PHASE 2 & as I ~ fI) (PROPOSE .r;

() C) - .-:z: " • " c(

" .. 0 'too

0 .r; fI)

c( , >0-.. co Q

LEGEND

o Access Points

• Existing P & R Lots o Proposed P & R Lots A Transit Center

0

-CD m -fD CD

==

3 ) PHASE 1

Katy Freeway

.. ~ CD () C 0 fI) fI) as CD -

C!J m

Figure 2: Katy Freeway Transitway, Phase Construction

>0-as

.r; J -.. CD 0 CD

fH-10 z .. u.

Downtown

By 1987 in the peak hour alone, the Katy Freeway Transitway should

accommodate approximately 60 buses and 190 vanpoo1s, or 3,900 persons. Daily

ridership could exceed 15,000 commuters. Peak hour travel time from the

Addicks Park-and-Ride lot to downtown, via the lane, will be reduced from the

current 45 mi nutes down to 25 mi nutes.(~)

North Freeway Transitway

The North Freeway currently carries more than 150,000 vehicles each

weekday. Population in the freeway corridor is expected to grow 38% by 1995,

and traffic vol urnes wi 11 increase according1y.OJ

The transitway will be built and operated in four phases (Figure 3).

Phases I and II include both transitway and main1ane construction, a total of

9.6 mil es from downtown to North Shepherd. Construction will begin in April

1983 and be completed in 1985. Phase III will extend the lane 4.9 miles from

North Shepherd to North Belt. And Phase IV will continue an additional

3.1 miles to Airtex. Phase III construction is scheduled to begin in January

1985 with a completion date in June 1986. Phase IV construction will begin

in May 1985 and end in June 1986.

The North Freeway Transitway wi 11 be constructed in the median of the

freeway and separated from general traffic lanes by concrete barriers. Since

the construction of the transitway is part of the SDHPT work to upgrade and

expand the North Freeway to eight lanes, disruption for building the lane

will be minimal. The North Freeway Transitway will significantly reduce peak

hour travel time. When completed, the travel time for transitway users

during peak periods will be half that for current main1ane users. The

transitway will also significantly increase the carrying capacity of the

freeway. During its first full year of operation, the North Freeway Transit

way is expected to benefit 26,000 commuters daily in vanpoo1s and buses.(l)

6

L..-. ______________________________________________ _

Kuykendahl

Stuebner· Airline

Alrtex

ender

" :x: l> tn m = -

" :x: l> tn m

<

----'1___ Little York

Shepherd Dr.

LEGEND Downtown

D Access Points e Existing P & R Lots

Figure 3: North Freeway Transitway, Phase Construction

7

Gulf Freeway Transitway

Currently, on the Gulf Freeway 150,000 vehicles travel the freeway each

weekday. Traffic in peak periods exceeds 1,900 vehicles per hour per

lane. (1)

The transitway will be built and operated in three phases as part of the

freeway reconstruction (Figure 4). The first phase stretches five miles from

Lockwood Drive to Airport Boulevard. Construction began in 1982 and is

scheduled to be completed in mid-1985. The second phase will extend the lane

2.5 miles from Lockwood to downtown; this section should open as an interim

facility in 1986. The eight-mi le third phase will extend the lane from

Airport Boulevard south to Choate Road near Ellington Air Force Base. This

phase may be built in segments as traffic demands dictate. The total tran

sitway will be 15.5 miles long when completed.

Four intermediate grade separated interchanges will allow direct access

to the transitway and connections to other transit faci 1 ities. Interchanges

at Lockwood, Hobby and Fuqua employ elevated ramps and bridges over the

freeway for entry and exit. Construction will include improvements to

genera 1 traffic freeway ramps and to intersections at severa 1 major cross

streets.

The Gulf Freeway Transitway will significantly reduce peak hour travel

time for users of the transitway. On the five-mile Phase I section, travel

time wi 11 be reduced 5 to 10 mi nutes. When all 15.5 mi 1 es are comp 1 eted, a

bus trip on the transitway to downtown should be about 13 minutes, half the

current time. The transitway will also significantly increase the carrying

capacity of the freeway. About 15,000 daily commuters are expected to travel

the lane in vanpools and buses during its first full year of operation. The

completed transitway should be able to move 30,000 commuters per hour in

buses and vans.(~J

8

LEGEND

• Interchanges • Existing P & R Lots

o Proposed P & R Lots

.& Transit Center

o Vanpool Staging Lots

Hobby Airport

Fuqua

Clear Lake City

Figure 4: Gulf Freeway Transitway, Phase Construction

9

STUDY DESIGN

Data Base

The fo1 lowing three general groups of data are being collected along the

Gu1 f, Katy and North Freeway corridors: (1) Park-and-Ride Demands, (2) Peak

and Off-Peak Direction Freeway Travel Times, and (3) Peak Direction Freeway

and Frontage Road Vehicle Volumes and Occupancies. The Park-and-Ride data

includes the number of vehicles parked in each of the surveyed lots, and the

time and date the lot was counted. The travel time surveys include the

collection of cumulative travel times at various check points along the study

corridors, the weather, 1 ight, and pavement conditions at the time of the

runs, and the severity of any incidents during the runs. Queueing and

stopped vehicle data have also been collected during these travel time runs.

Finally, in the vehicle volume and occupancy survey, main1ane occupancies and

volumes by vehicle types have been recorded. The frontage road volume is

also recorded without being categorized by vehicle type or by occupancy.

Collection Methodology

Beginning in June 1983, Park-and-Ride demand levels were sampled monthly

at two lots on the Gu1 f, two lots on the Katy, and four lots on the North

Freeway. These lots are shown in Figure 5. The samples were collected

between the morning and the evening peak periods (i.e. after 10:00 a.m. and

before 4:00 p.m.). In this study, the park-and-ride demand 1 eve1 s are being

represented by the number of vehicles found parked inside the park-and-ride

lots. The study is not sampling the demand for park-and-ride service,

rather, the demand for park-and-ride lot space. However, for lots not at

capacity, this provides a rough measure of demand.

11

61-10 5

PARK & RIDE LOCATIONS

o EXISTING LOTS (# spaces)

1 - Spring (1280) 2 - Kuykendahl (2246) 3 - N. Shepherd (1605) 4 - Seton Lake (1286) 5 - Mason (246) 6 - Katy at Hwy 6 (1119) 7 - Edgebrook (1000) 8 - Clear Lake (323)

rn 2

-• .. CJ1

Figure 5: Park-and-Ride Lot Locations

Freeway travel times are also being sampled on a monthly basis. All the

travel times are sampled near the middle of each month (i.e 2nd or 3rd

complete week of each month) with a specific day of the week assigned to each

freeway. The Katy Freeway travel times are always sampled on a Tuesday, the

North Freeway on a Wednesday, and the Gulf Freeway on a Thursday. This

sampling schedule screens out the daily and the weekly variations in travel

times that may be present and al lows one to see the monthly changes.

On the Gulf Freeway, the travel times from Choate Road to the Hogan

Street Overpass are being recorded. On the Katy Freeway, the travel times

are bei ng recorded from State Hi ghway 6 to Washi ngton Avenue. On the North

Freeway, the travel times are being recorded from the North Belt to the Hogan

S t r e e t 0 v e r pas s • Beg inn i n gat 6: 00 a. m., t r a vel tim e run s ea reb e gun a t 3 0

minute interva 1 s ending by 11 :00 a.m. In the afternoon, a 1 so at 30 minute

intervals, travel time runs are made between 4:00 p.m. and 8:00 p.m.

Cumulative travel times are recorded at sequential checkpoints in both the

inbound and outbound directions in the morning and in the afternoon. Terminal

checkpoints are shown in Figure 1, and all checkpoints with their associated

mile points are listed in Table 1. Each vehicle is manned by two people, so

that one person may record while the other is free to concentrate on driving

in rush hour traffic.

Freeway vehicle volumes and occupancies are being sampled on a quarterly

schedule at the following locations: (1) Gulf Freeway at Monroe, (2) Katy

Freeway at Bunker Hill, and (3) North Freeway at Little York. An initial

plan to sample on a monthly schedule was found to be infeasible because of

monetary and manpower restrictions. Further, it has proven difficult to

amass the manpower necessary to sample on a bi-monthly basis. Consequently,

13

TAELE 1. TRAva TIt.£: O£CK POINTS

Inbound

Gulf Katy North Milepoint Cross Street Milepoint Cross Street Milepoint Cross Street

0.00 Choate Road 0.00 SH6 0.00 North Belt 2.00 South Belt 1.63 Eldridge 1.70 west Road 4. 05 Almeda-Genoa 2.30 Dairy Ashford 2.90 West Mr. Houston 5.35 Edgebrook 3.28 Kirkwood 4.45 North Shepherd 6.25 Airport 4.18 Wilcrest 4. 95 Little York 8.15 Howard/Bellfort 4. 93 West Belt 5.75 Parker 9.05 Park Place 6. 08 Gessner 6.85 Tidwell

10.15 South Loop 6.81 Bunker Hill 7.75 Airline Drive 10.45 Reveille 7.44 Blalock 8.20 Crosstimbers 11.35 Griggs 8.80 Bingle 9.30 North Loop (I-610) 12.10 Wayside 9.62 Wirt 11.00 North Main 13.75 Calhoun 10.19 Antoine 12.20 Hogan st. Overpass 14. 50 Scott 10.64 Silber 15.30 Dowling 11.56 West Loop 16.85 Dallas 12.81 Washington 18.20 Hogan st. Overpass

Outbound

Gulf Katy North Milepoint Cross Street Milepoint Cross Street Milepoint Cross Street

0.00 Hogan st. Overpass 0.00 Washington 0.00 Hogan st. Overpass 1.35 Dallas 1.25 West Loop 1.20 North Main 2. 90 Dowling 2.17 Silber 2. 90 North Loop (I-610) 3.70 Scott 2. 62 Antoine 4.00 Crosstimbers 4. 45 Calhoun 3.19 Wirt 4. 45 Airline Drive 6.10 Wayside 4.01 Bingle 5.35 Tidwell 6.85 Griggs 5.37 Blalock 6.45 Parker 7.75 Reveille 6.00 Bunker Hill 7.25 Little York 8.05 South Loop 6. 73 Gessner 7.75 North Shepherd 9.15 Park Place 7.83 West Belt 9.30 West Mt. Houston

10.05 Howard/Bellfort 8.63 Wilcrest 10.50 West Road 11.95 Airport 9.53 Kirkwood 12.20 North Belt 12. 85 Edgebrook 10.51 Dairy Ashford 14.15 Almeda-Genoa 11.18 Eldridge 16.20 South Belt 12.81 SH 6 18.20 Choate Road

14

a three month schedule was selected. Volumes are counted for 15 minute inter

vals on a 1ane-by-1ane basis between 6:00-10:00 a.m. and between 4:00-7:00

p.m. These counts, 1 ike the park-and-ride and the travel time surveys, have

also been conducted in the 2nd and 3rd week of each month, with the same

specific day of the week being assigned to each freeway corridor. Due to

inadequate lighting conditions volumes could be recorded only from 6:30 to

9:30 a.m. and from 4:00 to 6:00 p.m. in the winter quarter. However, all

other quarters were sampled for a minimum of three full hours for each peak

period. To a1 low the afternoon winter data to reflect a full three hour peak

period, the 1 ast hour of data was extrapo1 ated from the data taken in pre

vious quarters and from the preceding two hours of winter quarter data.

Surveyors are stationed in the peak directions in the outer separation

between the freeway and the frontage road, or at sites on the other side of

the frontage road. Locations have been chosen just before or after the point

where the freeway crosses the survey street to maximize visibil ity of the

surveyed vehicles and the safety of the surveyors while minimizing the dis

ruption of norma 1 traffic flow. A surveyor is assigned to each peak direc

tion lane on the freeway, and one surveyor is assigned to the frontage road.

The surveyor counting the frontage road is also responsible for the contra

f1 ow vo 1 umes on the day that the North Freeway is counted. Surveyors must

record both the total number of vehicles of each type and the occupancies of

each vehicle type. These vehicle and occupancy classifications are listed in

Tab 1 e 2.

15

TAIl.E 2. Veaa...E 0CCtPAtI:Y CATEOJUES

Vehicle Categories Occupancy Categories

Pickups/Passenger Cars 1 2 3 4f.

Vans 1-3 4-6 7+

Buses Bnpty 1/4 full 1/2 full 3/4 full Full

Analysis Techniques

Regresslon techniques will be applied to all three general groups of

data. The resulting regression models will allow the investigation of the

statistical relationships between the variables of interest. They will be

used to determine the magnitude and significance of changes in travel times,

park-and-ride lot demands, and person volumes that may be attributed to the

operation of transitway projects. Additionally, the Tukey Multiple Compari-

son procedure will be used to compare the relative degrees of success of the

various different combi nations of design features.(~)

Park-and-ride demand levels will be regressed on three factors: (1)

time, (2) CFL operation, and (3) transitway operation. Time wi 11 be dis-

cretized by month. CFL and transitway operation will be indicator variables

with a value of one if the CFL or the transitway is in use and zero other-

wise. The two indicator variables permit the investigation of the unusually

steep gains in demand anticipated when priority vehicle lanes are opened to

authorized vehicles. The time variable simply estimates the general trend of

16

the surveyed park-and-ride demands. The regression relationships will be

used to project demand levels forward in time.

Overa 11 speeds wi 11 be regressed on: (1) the extent of construction

work, (2) the number of lanes taken for construction, (3) the weather condi

tions, (4) the 1 ighting conditions, (5) the pavement conditions, (6) the

severity of accidents or incidents, (7) the reduction of lane widths, (8) the

operation of the transitway in the corridor, and (9) the time of day. Since

speed is a function of both distance and travel time, regression will be

applied only to speed. The results will then be converted to travel time.

The first six variables take integer values from zero upwards as the condi

tions worsen. Lane width reduction and transitway operation are class vari

ables that will be converted into indicator variables to facilitate regres

sion analysis. They will take the value of one if lane widths have been

narrowed or if the transitway is operational and zero otherwise. Finally,

time of day simply will be the times when the travel time runs were started.

These travel time variables and their values are listed in Table 3.

Vehicle volumes and occupancies will undergo a similar regression analy

sis once an adequate data base is establ ished. Four variables will be ex

amined: (1) the total vehicle volume, (2) the total person volume, (3) the

overall average occupancy rate, and (4) the HOV contribution to each of the

preceding three variabl es. The independent variabl es wi 11 be: (1) the

extent/severity of construct ion (i .e. number and/or width of 1 anes reduced,

etc.), (2) the weather conditions, (3) the existence/severity of accidents or

other such disruptive incidents, (4) the operation of a CFL, and (5) the

operation of a transitway. The regression procedure is continued for this

group of data because of interest in both the presence and the magnitude of

any significant increases or decreases in volumes and occupancies of the

17

TABLE 3. TRAVEL TIME V ARIABLE5 AND VALUES

Weather (W): Extent of Construction Work:

o = Clear o = 0% of corridor length 1 = Overcast 1 = 25% of corridor length 2 = Light Rain or Drizzle 2 = 50% of corridor length 3 = Heavy Rain 3 = 75% of corridor length

4 = 100% of corridor length

Light Conditions (L): Lane Width Reduction:

o = Normal Daylight o = No lane width narrowing 1 = Dark or Twilight 1 = Lanes narrowed 2 = Sunglare 3 = Fog

Pavement Conditions (P) : Number of Lanes Removed:

o = Dry o = No lanes removed in any section 1 = Wet 1 = 1 lane removed in any section 2 = Ice, Snow or other extreme slickness 2 = 2 lanes removed in any section

3 = 3 lanes removed in any section

Incidents (I):

o = None 1 = Minor (off-road)

(No appreciable impact on speed) 2 = Major (lane blockage, etc.)

(Significant impact on speed)

imp lementation of transitways on the Katy and Gu lf Freeways, and after the

upgrading from CFL to transitway on the North Freeway. Fina lly, the Tukey

Multiple Comparison procedure is employed to identify any statistically

significant as we 11 as any practica lly significant differences between the

volume changes resulting from the three different transitway treatments.

Tables and plots illustrating relevent statistics will also be available

to supplement the statistical tests. For the park-and-ride demand data,

tables will be produced to display the monthly demand levels for each of the

18

lots as well as for the entire corridor. The plots will graphically il lus

trate the general trends in the corridor's park-and-ride parking demands as

compared to its capacity. Finally, the total parking demands for all three

corridors will be superimposed on the same graph to provide a rough visual

means of comparing the demand levels on the three corridors.

The travel time tables will summarize the average peak period and peak

hour travel times and speeds (on a section by section basis), total travel

times, and average travel speeds in both the peak and the off-peak direc

tions. Two of the graphs will illustrate the changes that the average speeds

and the total times have experienced each month. The third graph will plot

the section speeds by the milepoints. Each month's data will be represented

by a curve connecting the various monthly section speeds. The extent of the

transitway construction/road surface renovation will then be indicated on

these monthly curves. This last graph would illustrate the impact (if any)

that transitway construction has on freeway travel time for non-transitway

users.

Tables for the volume study will summarize peak period and peak hour

vehicle volumes, person volumes, HOV percent of vehicle volume, HOV percent

of person volume, and overall vehicle occupancy rates in the peak directions.

The accompanying graphs fall into three basic categories, those depicting (1)

vehicle and person volumes, (2) HOV percent of vehicle and person volumes,

and (3) overa 11 occupancy rates by vehicl e type. A separate set of graphs

wi 11 be pictured for each freeway, for each peak period and for each peak

hour.

19

PRELIMINARY RESULTS

Overview

At the beginning of this study in June 1983, two of the three study

corridors al ready had transitway construction work underway, and the third

had begun preconstruct ion work. The Gul f Freeway transitway construction

started as early as September 1982. The Katy Freeway had. its construction

ground breaking ceremonies in May 1983. The North Freeway preconstruction

preparatory work began in April 1983, but actual construction did not begin

until January 1984.

All three study corridors are heavily invol ved in actual transitway

construction now. However, only the Katy Freeway has experienced lane nar

rowing, restriping and traffic reassignment along extensive sections of its

length. While the Gulf Freeway has undergone spotty construction work mostly

around the Lockwood Interchange, the Katy Freeway has seen construction

extending from West Belt all the way in to Post Oak/West Loop during the

first six months of this study. Until January 1984, work on the North

Freeway consisted of the relocation of signing, lighting and guard railing

from its median. Although the North Freeway did not experience any extensive

construction through the first six months of this study, it has had an

operational HOV contraflow lane for more than five years. All three corri

dors are different, whether in operational characteristics or in functional

circumstances. All three are experiencing high degrees of traffic congestion

and the resulting unacceptable levels of service; installation of median

transitways should improve mobility on all three corridors.

21

Park-and-Ride Parking Demand

Figure 6 illustrates the variations in Park-and-Ride Demand for each

corridor on a monthly basis. All three corridors exhibit very small rates of

change per month. The Gu 1 f Corri dor has decreased s 1 i ght 1 y at a rate of 18

vehicles per month. The Katy Corridor has increased slightly at a rate of 10

vehicles per month, and the North Corridor has increased at a rate of 24

vehicl es per month. These slope estimates are very prel iminary since they

are based upon only 6 months of data. Any conclusions drawn at this time

lack reliability. Further inspection of the demand plots reveals that very

little notable variation can be seen from month to month. However, once the

transitways become operational, large monthly, if not weekly, increases in

park-and-ride demand are anticipated on the Katy and the Gulf Freeways.

Travel Times/Speeds

Figures 7 through 17 illustrate monthly changes in total travel times,

overall speeds, and sectional speeds that the Gulf and North Freeways have

experienced since June 1983, and the Katy Freeway since January 1982.

Gulf Fr>eeway

In Figure 7, the morning outbound and afternoon inbound total travel

times have shown no pronounced changes since June 1983. For the study length

of 18.20 miles, the estimated total time for a vehicle travel ing at 55 mph

would be 19.9 minutes. The off-peak direction travel times have fallen below

this mark in almost every month, although both rose above this mark in July

1983. The 6 month averages for the two off-peak direction travel times are

19.6 minutes in the morning and 20.3 minutes in the afternoon. Both averages

22

GULF CORRIDOR PARK-AND-RIDE DEMAND KA { , TV CO, RIDOR PAl {!\-AND- I RD EDL. A D

7000 7000

6000 6000

5000 5000

4000 4000

0 ~

0 0

:c ;; ~

;;-

3000 3000

2000 2000

GuH Corridor Park~and-Ride Capacitv- 1325 Vehicles }(aty Corridor Park-and-Ride Capacity- 1365 Vehicles

1000 1000 - - -. ~

0 0

Jun 83 Jul 83 Aug 83 Sep 83 Oct 83 NCo\. 83 Jun 83 Jul 83 Aug 83 Sop 83 Oct 83 Nov 83

Date

NORTH CORRIDOR PARK-AND-RIDE DEMAND

7000

North Corridor Park-and-Ride Capacitv= 6417 Vehicles

6000

5000

4000 ~ ~

u :;;

I~ u :> ~

3000

2000

1000

0

Jun 83 Jul 83 Aug 83 Sep 83 Oct 83 Nov 83

Date

Figure 6 : Park-and-Ride Demands in Study Corri dors

23

c ::;:

45

LEGEND:

GULF FREEWAY A.M. PEAK HOUR/PERIOD

TOTAL TRAVEL TIMES INBOUND

Peak Period 40 --- Peak Hour

//-- --/ 35

30 """"'" //// '

, , ... --------~

25

201~------------------------------------~5~5~M~P~H~-----

15

10~--------~----~--~----~~~----~~~--~~. Jun 83 Jul 83 Aug 83 Sep 83 Oct 83 ,-Nov 83

45

40

35

30

25

20 ,

15

LEGEND:

Date

GULF FREEWAY P.M. PEAK HOUR/PERIOD


Peak Period - - - Peak Hour

" , \ I \

I \ I \

I \ I \

I \

I ,

\

I \ , \

I \

I \ \ , \ , \ , \ ,

55 MPH

10Lr ________ ~--------------~--~----~_c~--~~ Jun 83 Jul 83 Aug 83 Sep 83 Oct 83 ,- Nov 83

Date

45

LEGEND:

GULF FREEWAY A.M. PEAK HOUR/PERIOD

TOTAL TRAVEL TIMES OUTBOUND


35

30

25

15

10~--------~----~--~~--~--~----~~~--~~ Jun 83 Jui 83 Aug 83 Sep 83 Oct 83 Nov 83

45

40

35

30

25

Date

GULF FREEWAY

LEGEND:

P.M. PEAK HOUR/PERIOD TOTAL TRAVEL TIMES

OUTBOUND

Peak Period Peak Hour

I" I \ , \

I \ , , I \

I \ , \ , \ , , I ,

/ \ , \ , , /' '\ //,/' ... _--------.... _--------, \./

20t-______________________________________ ~5~5~~~IP~H~ ____ __

15

~~Ln~8~3----~J-u~I~8~3----~A~u-g~8~3~--~S~.-p~8~3----~O~c-tC8~3~--~N~o-v-83

Date

Figure 7: Gulf Freeway Total Travel Times

24

are close to the desired free flow travel time of 19.9 minutes, based upon a

55 MPH speed 1 imit.

The peak direction travel times (morning inbound and afternoon outbound)

have not been as stable as the off-peak direction travel times. Both morning

and afternoon peak travel times have been increasing since June 1983. The

six month average for the morning peak direction is 25.2 minutes; for the

afternoon peak, it is 24.6 minutes. Both exceed the free flow time by

rough 1 y 25%.

Study of the average corridor speed graphs in Figure 8 indicates that

the increases in travel time discussed in the proceeding paragraphs are not

substantial when compared to the study length of the corridor. The average

Gulf corridor speeds are 46 MPH in the morning inbound direction, 47 MPH in

the afternoon outbound direction, 56 MPH in the morning outbound direction,

and 55 MPH in the afternoon inbound direction. The peak directions are

running close to 10 MPH less than the legal speed limit of 55 MPH, but the

off-peak directions appear to be operating very close to 55 MPH.

The plots of average peak period sectional travel speeds versus sec

tional cross street limitations in Figure 9 point out the problem areas along

the corridor. In the morning peak directions, the travel speeds consistently

drop to their minimums at Airport and at Scott. In the afternoon peak

direction, the worst slow-downs occur near Calhoun and at Howard/Bellfort,

just before Airport. The off-peak directions do not appear to have any

sections with substantial congestion at the present time. The peak hour sec

tional travel speeds plotted in Figure 10 show queueing at Edgebrook and

Calhoun in the morning inbound, and at Park Place and Howard/Bel 1 fort in the

afternoon outbound. The off-peak traffic flow shows no probl ems during the

peak hour.

25

0: :;:

70

60

LEGEND:

GULF FHEEWAY A.M. PEAK HOUH/PEHIOD

TRAVEL SPEEDS INBOUND

Peak Period --- Peak Hour

55~------------------------------------------------

40

-- ----30

-.., ....... ------_-..---

20

10

0L-________ --____________ ~--~--~~~--~~-Jun 83 Jul 83 Aug 83 Sep 83 Oct 83 Nov P3

70

60

LEGEND:


Date



55~'~~~------~~~~----~~---=~==~~~~~---\ ' \ I

50 \ I \ I

\ I \ I

\ I

\ / \ I \ I \ I

\ I

40

\ I

\I

30

20

10

°L~--~~~--~~--~~~--~~.__,On:S Jun 83 Jul 83 Aug 83 Sep 83 Oct 83 Nov 83

Date

70

60

50

40

30

20

10

LEGEND:

GULF FREEWAY A.M. PEAK HOUIVPERJOD

TRAVEL SPEEDS OUTBOUND


o~ ______ ~~ ____ ~~~ __ ~~~ __ ~--~--~~ Jun 83 JuJ 83 Aug 83 ~ep 83 Oct 83 Nov 83

70

60

LEGEND:


Date



55~-----------------------------------------

50

_~ ________ A--------~

20

10

0L-~ __ ~~~ __ ~~~ __ ~~~ __ ~~ __ ~~ Jun 83 Jul 83 Aug 83 Sep 83 Oct 83 Nov 83

Date

Figure 8: Gulf Freeway Overall Travel Speeds

26

70

60

50

40

30

20

10

0 ~ "" .,; 0 0

0: " 0 ., ~ .,

~ . ., 0 "0 "0 .c

E UJ ()

;;:

70

60

GULF FREEWAY A.~1. PEAK PERIOD

SECTION TRAVEL SPEEDS INBOUND

/\ 1./ I \, /,/

\ I' VI

~- .co. ., ., -0

~ ;;~ "0 0....l

.; ~= V> ~ '" 0., .,

~ :rill 0:

Cross Street

GULF FREEWAY P.M. PEAK PERIOD


LEGEND:

--JUN 83 _____ ·AUG 83 -·-NOV 83

" .,

" .: 0

== ~ 0 .

() Q

-~ V>~ . "0.

"" "'., 0> :ro

55~---------~----------~~----~--7-~~~~~--

50

40

30

20

10

0 . '" :at: .co. -d 0 0 " 0 -0 0: ~ ~

r._ '0 ~= ~..J

~ 0 0., ., ~ '" :rill

0

" "0 -" ()

., UJ E Cross ;;:

o! ., ~ Q;

'" ~

~ ., 0:

Street

LEGEND:

--JUN 83 ------ AUG 83 ---NOV 83

" '" " .: 0 ~ -" ;; 0

U Q

...:V-1/)0

r. ge-"'., 0> :rO

70

60

GULF FHEEWAY A.M. PEAK PEHIOD

SECTION TRAVEL SPEEDS OUTBOUND

;) £A>:~~ 55~---/----_-H~~~-_;r~-~~~~\I~--~-------

50 ~.-/

40

30

20

j -0 '" (/)0 " ge ~ ",., 0 O~ Q

:rO

70

30

20

10

0

":0 '" .: (/)0

c~ ~ r." 0 "''' Q O~

:rO

" .,

~ .co. . "0 -0 0 -;;; .; '0 .c '" ~ ~....l ~ ; 0:

Cross Street

GULF FREEWAY

, "0-

:;~ ~= 0., :r'"

LEGEND:

--JUN 83 ______ AUG 83

-·-NOV 83

'" . 0 0

~ " ., 0 ., ~ '" "0 "0

ILl ., E ;;:

P.M. PEAK PERIOD SECTION TRAVEL SPEEDS

OUTBOUND

" ., .,

-=0. . "0 -0

~ .~ Q; '0

'" ~ ~....l U ; .,

0:

Cross Street

~t: .0

~= 0., :rill

LEGEND: __ JUN 83 ______ AUG 83

-·-NOV 83

'" . 0 0

" ~ ., .D 0 .,

~ ., "0 .. "'

., e ;;:

.,; 0: . ;; 0 .c U

" c: ., c 0 .c u

Figure 9: Gulf Freeway Peak Period Section Travel Speeds

27

,----------- ~ ----- -

70

60

55

50

40

:t 0-:;:

30

20

10

0

.,; 0: ~

" 0 .<: (J

70

60

55

50

40

:t 0-:;:

30

20

10

0

.,; 0:

~ 0

.<: (J

~ .>: 0 0

~ £ ~ .g

Ol

"" "" ~ UJ E

~ '" 0 0 c

~ ~

~ '" ." ." ~ UJ E ;;:

GULF FREEWAY A.M. PEAK HOUR


1/

I I

I I I

I r--J

I I

I

/j'\ .I / . /

j \

~t: .<:0. ~ -0 • 0

"- "0 .. ~= ~ ... > o ~ . :t", 0:

Cross Street

:GULF FREEWAY P.M. PEAK HOUR

~

~ '" " !3

LEGEND:

--- JUN 83 ------ AUG 83 --·-NOV 83

C Ol

" .= 0 ~ .<:

OJ 0 (J A


LEGEND: ___ JUN 83 ______ AUG 83 __ NOV 83

:Ct: ., .co. . ~ c ·0 -0 "" " c

"'" "- "0 ;;; 0 . 3= ~ ... . .c ~ ~~ ~ '" o~ . OJ 0 "'. :t'" '" !3 (J e 0>

:to

Cross Street

~~

"'~ . ~e-Ol. 0> :to

:t 0-:;:

70

(,0

GULF fHEEWAY A.M. PEAK HOUR


,,~~. /,

1\ r ~,,~ // j \/\ " '\i~___ /'-. ;/

/ ~. /~~ 55~ ______ -L __ ~ __ ~_~~L-------~--~~-------------\ / '~<J\' -r // '/' 50

40

30

20

)0

0

.;~ Vl~

c:;' .. .,. 0> :to

70

60

55

50

40

30

20

10

0

.;~ "'. c· .e Ol. 0> :to

: '-/ \. '--...... I "

/\ / \/

., .= "3 0 e

c ~ ~ .<:0. :;;~

" "" -0 .. 0 .; .. "0 .0

.<: '" > ~ ... ~= -;; ~ . O~ (J !3 0: :t'"

Cross Street

GULF FREEWAY P.M. PEAK HOUR


LEGEND:

--- JUN 83 ------ AUG 83 -~-NOV 83

"'" ~

0 0 c e

.D C; ~ :. Ol

"" :'" UJ e

;;:

.,; 0: . " 0 .. U

, I

I

}/ r:7!----

Ol .= "3 0 e

c . ~ .co.. " "" -0 ,g ~ .. "0 . . ~ ~ ... (J ~ 0:

Cross Street

:;;~ .. .0

~= o. :tel

LEGEND:

--- JUN 83 ------ AUG 83 -'-NOV 83

oX " 0 0 c £ ~

.D (!) . ~. '" ."

UJ e ;;:

Figure 10: Gulf Freeway Peak Hour Section Travel Speeds

28

Katy FpBBway

In addition to the Texas Transportation Institute (TTl) data collected

since June 1983, it has also been possible to obtain peak hour peak direction

travel time and speed data from the SDHPT. These times and speeds are

plotted in Figures 11 and 12. That data goes back as far as January 1982 and

extends to the end of 1983. The picture presented by these two years of data

is ambiguous. No distinct trends are apparent. The 1982 data shows the Katy

Freeway operating no better and no worse than in 1983. The average 1982

travel times were only about one minute more than the 1983 travel times; and

the 1982 travel speeds were only about one MPH faster in the morning and 1

MPH slower in the afternoon than the 1983 travel speeds. Despite the

transitway construction, the overall 1983 traffic conditions in terms of

travel time have not deteriorated substantially.

The Katy Freeway study length is 12.81 miles. A car traveling at 55 MPH

over this distance would have a travel time of 14.0 minutes. In Figure 13,

the off-peak direction travel times are near 14.0 minutes, but both peak

direction travel times exceed this mark considerably. The morning off-peak

direction travel times have been holding steady near the free flow time, but

the afternoon inbound direction travel times appear to be increasing. The 6

month average for the morning outbound direction is 14.2 minutes and 14.6

minutes for the afternoon off-peak direction. Both averages 1 ie above the

free flow time but not by a substantial amount.

Peak hour, peak direction travel times from January 1982 to December

1983 are plotted in Figure 11, and peak period/hour times from June 1983 to

November 1983 are plotted in Figure 13. The morning and afternoon peak

direction data are very dissimilar. Whereas the afternoon peak direction

times appears to be decreasing throughout the two year period, the morning

peak direction times seem to have two different slopes. In Figure 11, the

29

w 0

III ~ ... ::J C

::E

45

40

35

30

25

20

15

KATY FREEWAY A.M. PEAK HOUR

TRAVEL TIMES INBOUND

55 MPH

Construction

10L-~----~--~----,-----~--~~~~---Jan 82 May 82 Sep 82 Jan 83 May 83 Sep 83 Dec 83

DATE

Source: SDHPT

III ~ ... :I c

::E

45

40

35

30

25

20

15

KATY FREEWAY P.M. PEAK HOUR TRA VEL TIMES

OUTBOUND

1 Year Pre-Data

Stud Period

Construction

55 MPH

10L-~--~-L--~---.----~--~~~~---Jan 82 May 82 Sep 82 Jan 83 May 83 Sep 83 Dec 83

DATE

Figure 11: Katy Freeway 1982-1983 Peak Hour Total Travel Times

:z: CI.

w ::e: I-' .

70

60

55

50

40

30

20

10

KATY FREEWAY A.M. PEAK HOUR TRAVEL SPEEDS

INBOUND

1 Year Pre-Data

Stud Period

Construction

O~-r----~~--~----~----~--~~~~---Jan 82 May 82 Sep 82 Jan 83 May 83 Sep 83 Jan 84

DATE

Source: SDHPT

:z: CI. ::e:

70

60

55

50

40

30

20

10

KATY FREEWAY P.M. PEAK HOUR TRA VEL SPEEDS

OUTBOUND

1 Year Pre-Data

Study Period

Construction

O~~~~~~~~--~----~ __ ~ __ ~~ __ _ Jan 82 May 82 Sep 82 Jan 83 May 83 Sep 83 Jan 84

DATE

Figure 12: Katy Freeway 1982-1983 Peak Hour Overall Travel Speeds

45

LEGEND,

KATY FREEWAY A.M. PEAK HOUR/PERIOD

TOTAL TRAVEL TI1·IES INBOUND

- Peak Period 40 --- Peak Hour " I ,

I , I ,

I , I ,

I ,

/ " ""'/"" ...... I 'I""' ...

/ " /-/ .....

35

I /

~ 30 """<",, I

I I

I I

.= ::;:

25 "-

2

15

I I

---J

55 MPH

]Ju~n~B~3~----J-U-lr8-3-------A-U~g-8-3------S-e-p~8-3------0~c~t8-3------N-o-,v 83

Date

KATY FREEWAY P.M. PEAK HOUR/PERIOD

TOTAL TRAVEL TIMES 45 INBOUND

LEGEND,

Peak Period

40 --- Peak Hour

35

30

25

2

_A

15 __ -Y---~~----+------ -------

10~------~------~------~~~--~~~--~~ Jun 83 Jut 83 Aug 83 Sep 83 Oct 83 Nov 83

Date

45

40

35

30

25

2

]5

LEGEND,

KATY rH!:! \'~'.".Y

A.M. PEA" HOUi:il'l.l,iOD TOTAL THAVEL TIMES

OUTBOUND

- ?eak Period --- l'cak Hour

_----S:LMPH------ __

IJ"~n~8~3----~J-u'I-8-3------A--Ug~B-3------S-c-pr-83------~O-c't~B-3------N-o-v~83

45

Date

I(ATY FREEWAY P.M. PEAK HOUR/PERIOD

TOTAL THAVEL TIMES OUTBOUND


35

30

25

2

15 55 MPH

10~--------r-------~--------~~--_=~~----~ Jun 83 Jul 83 Aug 83 Sep 83 Oct 83 Nov 83

Date

Figure 13: Katy Freeway Total Travel Times

32

1982 times appear to be declining while the 1983 times appear to be in

creasing. There is also a great deal more variation in the morning times

than in the afternoon times. Although the afternoon times varied only be

tween 27 and 37 minutes, the morning times ranged from 24 to 42 minutes. The

1982 average peak direction travel time was 31.1 minutes in the morning and

31.7 minutes in the afternoon. The 1983 peak travel times averaged 30.7

minutes in the morning and 30.2 minutes in the afternoon. One characteristic

that both peaks have in common is that they both climbed sharply for two to

three months after extensive transitway construction began. After these few

months, times dropped back to their previous levels. Drivers appear to have

adjusted to the unfavorable driving conditions (e.g. reduced lane widths)

within these few months.

As in the case with the Gulf Freeway, the speed plots in Figures 12

(182- 183 peak hour) and 14 (183 peak period/hour) reduce the magnitude of the

monthly travel time changes. The off-peak direction travel speeds both hover

around the 55 MPH mark a 1 though the 1 ast two months (October and No vember

183) have dropped to 50 MPH in the afternoon inbound direction. The morning

peak direction speeds averaged 27 MPH in 1982 and 25 MPH in 1983. The

afternoon peak direction speeds averaged 26 MPH in 1982 and 27 MPH in 1983.

These speeds are less than half the legal speed limit.

The average peak period, peak direction speed versus cross street plots

in Figure 15 indicate speeds below 30 MPH occurring between Kirkwood and

Antoine in the morning and from West Loop to Wilcrest in the afternoon. This

suggests that the Katy Freeway is operating in or close to a queue state for

almost 60% of its length in both peak directions. The off-peak direction

plots do not indicate any major problems. The peak hour sectional travel

speeds plotted in Figure 16 show queueing from Antoine to Wilcrest in the

33

:c ";:;:

70

60

LEGEND;

KATY FREEW,\Y A.M. PEAK HOUfUPLHIOD



55~------------------------------------------------

50

40~

30

--_ ...... _---20

10

o JuLn~83~----~J~ucJ~8~3------A~U-g~8~3----~S~e-p~8~3----~O~c-t-8~3~--~~N-o-v-83

70

60

50

40

30

20

10

LEGEND,

Date


TRA VEL SPEEDS INBOUND

- Peak Period --- Peak Hour --_ ...... ---------...... -

o Ju:n~8~3~----J~u~J~8~3~----A~U-g~8~3~----S~c-p~8~3------0--c-t-8-3------N-o-v-83

Date

:c "-;:;:

:c "-;:;:

I{ATY FHEEI'.'AY A.M. PEAl{ HOUR/PERIOD

TRAVEL SPEEDS 70 OUTBOUND

LEGEND,

Peak PeTiod 60 Peak Hour ..... 55 '--. --- -- --- ----50

40

30

20

10

0 Jun 83 Jul 83 Aug 83 Sep 83 Oct 83

70

60

LEGEND,

Date




.....

Nov 83

55r----------------------------------------------

50

40

"-, -, " -_ ............. - -30 - --- -, -.... --------... - " ---........ ---

20

10

0 Jun 83 JuJ 83 Aug 83 Sep 83 Oct 83 Nov 83

Date

Figure 14: Katy Freeway Overall Travel Speeds

34

70

60

KATY FREEWAY A.M. PEAK PERIOD


---. 55r------\~,~------------------------------~-----

50

40

30 , , , , ,

\

\ \ \ \ \ \ \

~ 20 \ \ , ,

\" ............ <J~

10

0 .;, W ." ., 0 :c ~ 0 VJ 3

'" -:; OJ :;:

70

60 #---:.::-. 55

50

40

:c "-:;:

30

20

10

0

'" w .., ., 0 :c ~ 0 VJ 3 .., -:;

iii :;:

LEGEND:

--JUN 83 ------AUG 83 ----NOV 83

~ W W '" C ;; i .. c 0

~ III c c '0 0 · ,.J ~ · ~ ~ "

c . w ~ w (!) '" « . ~ c w

~ ~ ~ III

Cross Street

KATY FREEWAY P.M. PEAK PERIOD


w ~ w .. ~ :c III c · " ~ w .

<3 '" w c ~ ~

til

Cross Street

LEGEND:

--JUN 83 ------AUG 83 -·-NOV 83

w '" c c 0 0

'0 0 .. ,.J c

" :a' « ., w ~ . ~

70

60

55

50

40 :c 0.. :;:

30

20

10

0 C '" ~ 0

0

-: c

~ w ~

E!

70

60

I,ATY FREEWAY A.M. PEAK PERIOD


~-f""-·'--..·--

W c '0

" «

W W .. i w

c :: III

III w w . '" (!) w ~ ~

til

rrro .. ", ~, .. "' ...

KATY FREEWAY

.., 0 0 3

-:; :;:

LEGEND:

---JUN 83 ------ AUG 83 --'-NOV 83

W .., '" ~ :c

V) .., iii

P.M. PEAK PERIOD SECTION TRAVEL SPEEDS

OUTBOUND

55r--------------------------------------7L---~---

50

40

30

20

10

0 c

~ c

~ .. ~

\ ' \ ~, \ ~ ~' \ // '~.:.;!'l \ ./ \ / \ / \ / \ I \ I

~\ . /'......... / \ / .'-.,/ , \ ./ ;

. \ -,,,,--,--/ ///

L _____ ~,/~----_/

'" ~ w w 0; 0 ~ i 0 '2 :: III -: t; .;: w <3 . w '" ~ E! c

~

til

Cross Street

LEGEND:

--JUN 83 ------AUG 83 --·-NOV 83

.., w 0 ., 0 ~ :c 3 V)

-:; .., iii :;:

Figure 15: Katy Freeway Peak Period Section Travel Speeds

35

0. ~

70

60

55

50

40

30

20

10

0

'" l: <J)

70

60

KATY FREEWAY A.M. PEAK HOUR


/. /.

//,' / ~\

~ ." 0) 0

:;: 0 a ." -:: ;;; :;:

.~ / , . \

I. / \

I ! I j

.~ .~. / .-/' ""'-. j' LEGENP:

'--. -- JUN 83 -----. AUG 83 -·-NOV 83

~ ~ " " ;; ~ l: 0, '0 '" : c

C ;;; ~ ~ ~

<t '" ~ " c 3 . '"

Cross Street

KATY FREEWAY P.M. PEAK HOUR


C-0 0 ..J

~

~

\ \

C

!'! '" .: ~

3

~-55J------~_ \~_+---~~~----~~~-~~'--,~\----50

40

30

20

10

0

" '" l: :;: <J)

'" ;;;

." 0 0 a -:: :;:

\ \ \ I

;;

'" ~

~

\ ) 'v

~

: ~

" Cross

~

i 0, c

" co ~

" c • co Street

\ \

V

LEGEND:

--JUN 83 ------AUG 83 ----NOV 83

c- c ~ c 0 0

0 C. 2 ..J c c

~ 0( ~ ~

~ ~

0. ::;:

70

60

55

50

40

30

20

10

0 C 0-0 0 ;;, 0 c -= ~

~

~ 3

70

60

l<ATY FREEWAY A.M. PEAK HOUR


A ;:_ ./

/' \, /'--. t- _ ~ ./f! '~ /" J \; .1---. I ~

~ c (; C <t

~ ~ 0. i ~

LEGEND:

-- JUN 83 ------AUG 83 -·-NOV 83

." ~ 0 '" 0

'" l: c ~ '" :;: " a

." ~.

'" ~ " ~ -:: " " ~ c :;: 3 • '" er05S Street

KATY FREEWAY P.M. PEAK HOUR


;;;

55;}-----,;---------------------------r~~~--------

50

40

30

20

10

0 c 0

C. c .c 0 . 3

I I

I I

I I

//

c-0 0

..J

~

~

j\ . \

/ \ . \ / \ /. . 1,/

~ ~ c

'" (; c C '" <t

~ i :: " ~ ~

" c . '" Cross

.\ // / . / / \. /

,1

1" I

I I

I I

~

co ~

~

~

Street

LEGEND:

--JUN 83 ------AUG 83 ---NOV 83

." ~ 0 0 ~ a -:: ."

;;; :;:

l: (J)

Figure 16: Katy Freeway Peak Hour Section Travel Speeds

36

morning inbound direction and from Kirkwood to Antoine in the afternoon

outbound direction. The peak hour, off-peak directions have been fairly

stable except in November when the afternoon inbound developed some problems

at Gessner and Wirt and showed a general degradation of speeds throughout the

transitway construction areas.

NOr'th Fr'eeUJay

The North Freeway study 1 ength is 12.20 mi 1 es with a free flow 55 MPH

travel time of 13.3 minutes. The six months of travel time data plotted in

Figure 17 exhibits a scatter from 15 to 25 minutes with an average of 20.1

minutes in the morning inbound direction. This average time translates to

almost 7 minutes of delay incurred by the average peak direction morning non

contraflow driver. The morning inbound direction travel times are increasing

at a rate of 0.5 minutes per month. The afternoon outbound direction main

lane travel times with an average of 19.5 minutes have also shown a scatter

of data points similar to the morning peak data. A rough trend estimate

would indicate that times could be increasing at a rate of close to 1.0

minute per month. However, this estimate, like the peak morning estimate, is

not reliable given the small data base.

In Figure 18, the 6 month average speed for the morning inbound traffic

is 42 MPH. The afternoon 6 month average outbound corridor speed is 33 MPH,

22 MPH less than the legal speed limit. There could be decreasing trends in

both the morning and the afternoon speeds, but as with the time data, these

tendencies are not clear.

The average peak period speed versus cross street plots in Figure 19 for

the North Freeway show the slowest speeds occurring from West Road to North

Shepherd in the morning inbound direction, and from Airline to West Road in

the afternoon outbound direction. The peak hour sectional travel speed plots

37

0

:;:

45

40

35

30

25

2

IS

---

LEGEND:

NOltTlI FHEEWAY A.M. PEAK HOUR/PEIlIOD


Peak Period ., f' Peak Hour

I I

I I

I I

I I

I f

I \ \

\ \ , ,

\ ,

-------~ I , I , f ,

I , , f , , f , f , , , I , , f )/

\ \

\ ... \ -'v--

55 MPH

10~ ______ ~r-______ ~ ______ ~~~ __ ~~~ __ ~~ Jun 83 Jul 83 Aug 83 Sep 83 Oct 83 Nov 83

45

40

35

30

25

2

15

-. Peak P~riod --- Peak Hour

---

Date

NORTH FREEWAY P.M. PEAK HOUR/PERIOD


55 MPH •..

10~--------r-------~--------~~--~ __ ~--~~ Jun 83 Jul 83 Aug 83 Sep 83 Oct 83 Nov 83

Date

c :;:

NORTH rri[,;"';,Y A.~1. PEAK IIOUH/PEIlIOD

TOTAL TRAVEL TIMES 45 OUTBOUND

LEGEND: 40


35

30

25

• , , 20

, , , , , , , .......... ------, ~ - ----,

15 ,

10~--------._------____ ----~~~----~~~--~~ Jun 83 Jul 83 Aug 83 Sep 83 Oct 83 .0 Nov 83

45

40

35

30

25

2

15

- Peak Period --- Peak Hour

-------- .......

Date


TOTAL TRAVEL TIMES OUTBOUND

55 MPH

IJuln~8-3------J-U'lr8-3------A~U~9~8~3~--~S~e-p~8~3-----;O~c~t~8~3~---:N~o~v 83

Date

Figure 17: North Freeway Total Travel Times

38

70

60

LEGEND:

NORTH FREEWAY A.M. PEAl{ HOUR/PERIOD

TRA VEL SPEEDS INBOUND

Peak Period - - - Peak Hour

55~---------------------------------------------------

50

/\ 40 ... \

/ \

/ \ / \

/ \ / \

30 ... \ -------~ \

\ " //'".,".,..--------

\ , 20

\ ~ .. /

10

o JuLn~8~3------J~u~J~8~3~----A~U~g8~3~--~S~c-p~8~3----~O~c-t~8~3~--~N~ov~83

Date

70

60

LEGEND:




55t-------------------------------------------------50

40

30 ~ ______________ _

20

10

--- ... --_...--------.

---.... -... ~-

o JuLn~8~3-----~.J~U7J~8~3~----A~u9~8~3~--~S~e-p--8~3----~O-c-t-8-3------N--ov--83

Date

Figure 18: North Freeway Overall Travel Speeds

39

"' c.. :;:

70

60

55

50

40

30

20

10

0

."

~ ~ 0 OJ to

'" 0 0

z ::

NORTH FREEWAY A.M. PEAK PEHIOD


I I

/""-/J /"

\--~---/

~

.: <:

Cross Street

NORTH FREEWAY P.M. PEAK PERIOD

, I

SECTION TRAVEL SPEEDS

LEGEND:

--JUN 83 -----. A UG 83 ---NOV 83

Q. o o .... t o Z

70

l INBOUND

:: -~~-/~.~--------------~/7~~'~L~~~----50 ~ \ 11/ \;;'~

\\ ;j/ 40

30

20

10

~

OJ

t o Z

" ~ o 0:

~,\ . /

\ .JI/ £==--;:;

- /

I I

I

,--_ .....

I

\ " V

.z~ "", OQ. Z~

'" tI)

~

~ a-

Cross Street

~

~ ;(

LEGEND:

--JUN 83 ------ AUG 83 -'-NOV 83

Q. 0 0 .... t 0 z

.~

- 0 tI)~ oc. ~ " tn· O~ :cO

:c "-:;:

70

60

55 50

40

30

20

10

0

';0 c. tl)0 0

~ 0 co. ..J ~ " "'~ .z o ~ :cO <;

z

70

60

NORTH FREEWAY A.M. PEAK PERIOD


LEGEND:

--JUN 83 ------AUG 83 -·-NOV 83

. ;; ." .: ","

~ !:~ 00. <: a- z~

'" tI)

Cross Street

NORTH FREEWAY P.M. PEAK PERIOD


~ 0 0:

0 ~

::

.. OJ

.z <; z

55,~----------------------------------------~~-----

50

40

30

20

10

0

';0 Co ~

V>~ 0 c 0

o Co ..J Co " ;( ",0 t 0' :cO 0

Z Cross

~

-:: ~

a-

Street

LEGEND:

--JUN 83 _____ .AUG 83

---NOV 83

" ~ ","

-~ 0

"'" 0: OQ. Z~

0 '" tI) " ::

.. III

t 0 z

Figure 19: North Freeway Peak Period Section Travel Speeds

40

in Figure 20 show substantial slowdowns extending from West Road to Airline

in the morning inbound direction and from the North Loop to West Road in the

afternoon outbound direction.

Contraflow lane Transition

The upgrading of the North Freeway contraf10w lane (CFL) to a transitway

is being monitored for its impact on the off-peak direction travel times and

speeds. The off-peak direction traffic on the North Freeway has had to cope

with one less lane than was originally a1 located to it. Since August 1979,

the North Freeway has had a CFL operating during both the morning and after

noon peak periods. Resulting from this reduction in roadway capacity and the

continued growth of travel demand in the off-peak directions, the morning and

afternoon off-peak direction travel times and speeds for the North Freeway in

Figures 17 and 18 have exhibited strong signs of deteriorating service

levels.

The morning outbound travel times have risen above the free flow mark in

every survey month. The average time from June to November 1983 was 14.8

minutes, almost two minutes more than the free flow time of 13.3 minutes.

Aside from the average delay of 2 minutes, the morning outbound data does not

yet suggest any appreciable deterioration in level of service. The 6 month

a v erage for the afternoon inbound is 19.5 mi nutes (a de 1 ay of more than 6

minutes) with a trend towards increased travel times. Such a trend confirms

that the contraf1 ow operation cannot continue to take a 1 ane from the off

peak direction traffic indefinitely without continued degradation of service.

The morning outbound lanes are operating relatively smoothly with an

average speed of 51 MPH. The afternoon inbound lanes have not coped with the

loss of capacity as well as the morning outbound lanes. With conditions

worse than the morning inbound lanes, the afternoon inbound lanes have a 6

41

70

60

50

40

X "-:;:

30

20

10

0

;;

'" -: 0 z

70

60

55

50

40

X "-:;:

30

20

10

0

0;

'" -: 0 Z

NORTH FBEEWAY A.M. PEAK HOUR


"-I , I " , /

'- / , -- -J

I I ,

" /A. ,

\ \ , - / \ \ /' \

'-.. / /', ,/ /1 \ ~ /

'~ V;I ~

/ \ \

1"-,,/

\ ;j \ \/ LEGEND:

--JUN 83 ------AUG 83 -'-NOV 83

" " ~ "- ..;: " . .<:" ~ c 0 ~~ ~ 0 "' .. 0 ".<: ...l co. c: 00. . ;;: ." z. "- -: ",.

0 .<: O~

~ (j) 0 :cO

z Cross Street

NORTH FREEWAY P.M. PEAK HOUR


~ / /

I \ ,< \ I \

\ \ \

\ \ I , , \ , \ \ ,

/ I \ I

I \ ;j~..... "-.J I

,

\\ 1/" I

\ I ,,~---/ Iy

LEGEND:

--JUN 83 ------AUG 83 --NOV 83

" "" ~ .. 0. ..:: 0 .<:"

~ 0

0 ~~ -; 0 "'. ".c 0: 00. .. ...l co. Z .. "- .. -: .. "

~ .c ",. ~ '" 0'

0 xO z

Cross Street

70

, , , 60 "'-.'

'-\-'" 55

\ 50

\ \ \ 40

\ \

0: \ L

\ 30

20 \ 10

0

.;~ "-",0 0 .. 0 Co. ...l 0" "," -: 0' xO 0

Z

70

60

55

50

40

X 0. :;:

30

20

10

0

';0 "-0 (j)~ 0

c c. ...l .. " -: ~~ xO 0

Z

NORTH FllEEIVAY

A.M. PEAK HOUB SECTION TRAVEL SPEEDS

OUTBOUND 1\ J \ 1 \ 1 \

F~ 1 \ I \

I,' '" \ I I , J , I \ .? , I \ 1 r;' , 1

. \ / \ \ I

J \rf--\ J

\ . ~

/ V

LEGEND:

--JUN 83 ------ AUG 83 -·-NOV 83

~ " " " ~ .. ~ ~

.<:" 0 ~~ .. _.<: 0: ;;: 00.

"- z~ .<: 0

'" .. ~

Cross Street

NORTH FREEWAY P.M_ PEAK HOUR


;;

'" -: 0 z

LEGEND:

--JUN83 ------ AUG S3 -'-NOV 83

. ~ " ." 0;

~ .<:" .. ~ ~ .. 0

'" .. ".c 0: :::: "-

00. -: z .. :;; .<: .. (j) 0 ~ Z

Cross Street

Figure 20: North Free0ay Peak Hour Section Travel Speeds

42

month average speed of 40 MPH. This is more than 15 MPH less than the speed

limit, and this gap is still increasing. In particular, as indicated in

Figure 19, average speeds close to and below 30 MPH are occurring from the

North Loop to Parker in the morning outbound lanes and from North Shepherd to

Parker in the afternoon inbound lanes. The peak hour off-peak direction

plots in Figure 20 show substantial speed reductions occurring between the

North Loop and Parker in the morning outbound direction and between West Road

and Airline in the afternoon inbound direction. Even a cursory examination

of the off-peak direction travel times and speeds strongly indicates that

upgrading the North Freeway CFL to a transitway is highly desirable.

Vehicle and Person Volumes

Unlike the Park-and-Ride and the Travel Time Surveys, the Volume Survey

is being conducted on a quarterly basis. The preliminary look at the volumes

occurred in June 1983. Since then, quarterly sampl ing, beginning in August

1983, has been initiated. The following analysis consists of three parts for

each freeway and each peak period: (1) an analysis of the vehicle and person

volumes, (2) an analysis of HOV contributions to overall vehicle and person

volumes, and (3) an analysis of the resulting occupancy levels. Since only 3

months of data have been collected to date, plots of the volume data will be

of either value, and therfore, are not presented in this report.

Gu'lf Fr>eeway

Peak period vehicle volume has oscillated noticeably in the 3 months of

data coll ected on the Gul f Freeway. In the morning peak period (6:30-9:30

a.m.), vehicle volume dipped as low as 11,400 and climbed as high as 12,800

43

vehicles. The person volume has not varied as erratically. It has increased

steadily from 14,700 persons in June to 16,400 persons in November. These

increases are traceable to monthly increases in HOV traffic. The HOV contri

bution to vehicle volume reached its highest level of 0.9% in November while

contributing to 7.9% of the person volume in the same month. Not unexpected

ly, within the HOV category, vanpools contributed more to vehicle volume and

buses contributed more to person volume. Throughout this study, the overall

occupancy rate in the morning peak period has hovered about 1.3 persons per

vehicle. No strong trends can be discerned at this early stage of the study.

The afternoon peak period (4:00-7:00 p.m.) traffic characteristics are

similar to the morning characteristics. Vehicle volume displays an even more

pronounced pattern of change than the morning data exhibited. Vehicle volume

has dropped as low as 9,500 vehicle in August and has jumped as high as

16,000 vehicles in November. Afternoon peak period person volume closely

mimics the behavior of the vehicle volume. It varied from 13,300 to 21,400

persons, a difference of close to 1,000 persons per hour per lane. These

variations in volume were also evidenced in the HOV data, though perhaps not

as strongly. HOVs contributed as much as 0.9% to vehicle volumes in Novem

ber. At the same time, they contributed to more than 8% of the person volume

on the Gulf Freeway. Overall occupancies, have remained close to 1.4 persons

per vehicle in the afternoon peak period. Statistics for the morning and

afternoon peak hour (beginning around 6:30-7:00 in the morning and 4:30-5:00

in the afternoon) approximate the peak period statistics with slightly higher

HOV statistics.

44

Ka ty Froeeway

Morning peak period vehicle volume has decl ined on the Katy Freeway

since June, 1983. Between June and August, morning peak period vehicle

volume dropped from 11,600 to 10,900 vehicles. In November the decline

continued although at a much slower rate. This decline could be related to

the 1 engthy transitway construction occurring on the Katy Freeway which has

required measures such as reducing lane widths and utilizing emergency shoul

ders for through traffic along various portions of the freeway. Despite the

decreases in vehicle volume, person volume has essentially remained constant

at about 13,800 persons. This relative lack of change in person volume

despite a decline in vehicle volume may be attributed to the steady gains in

HOV traffic and HOV average occupancy levels. The HOV contribution to

vehicle volume has varied from 0.5% to 0.6%. However, the HOV contribution

to person volume has steadily climbed from 5.4% in June, to 5.9% in August,

and to 7.8% in November. In June, the overall occupancy level was close to

1.2 persons per vehicl e, but in August and November the morning peak period

occupancy rate rose to 1.3 persons per vehicl e.

The morning peak hour shifted progressively later in the morning from

6:30 to 7:00 to 8:30. Within these peak hours the overall occupancy rates

have been around 1.3 persons per vehicle, but the HOV contribution to vehicle

and person volume has dropped sharply. The differences in peak hour and peak

period HOV statistics suggest that HOV traffic possesses different charac

teristics from the overall traffic. In particular, the HOV traffic appears

to be peaking earlier than the general traffic stream.

In the afternoon peak period, vehicle volume dropped sharply in August

(from 12,400 to 11,400 vehicles) and then rose even more sharply in November

45

to 14,700 vehi c 1 es. Passenger vo 1 ume fo 11 owed the same pattern and dropped

from 16,500 persons to 15,900, only to rise again to 19,400 persons. The HOV

contribution to vehicle volume has risen steadily from 0.5% in June to 0.8%

in November. The HOV contribution to person volume has also increased be

tween June and November (from 5.8% to 7.3%), but in August it reached its

highest of 8.8%. The high HOV contribution to person vol ume in August was

primarily the result of an unusually high bus occupancy rate in that month.

The overall occupancy rate has varied from 1.3 to 1.4 persons per vehicle in

the three study months.

NO'Y'th F'Y'eeway

The data obtained on the North Freeway includes the buses and vanpoo1s

in the contraf1ow lane (CFL) which operates between 6:00-8:30 a.m. and 4:00-

6:30 p.m. on the North Freeway. Most of the HOV vo 1 ume on the North Freeway

is found in the CFL. In fact, less than 10% of all the HOV volume may be

found in the unrestricted lanes on the North Freeway.

Morning peak period vehicle volume started at 11,300 vehicles in June,

dropped to 11,000 vehicles in August, and c1 imbed to 13,500 vehicles in

November. At the same time, person vo 1 ume began at 17,500 in June, dropped

to 10,600, and then rose again to 18,300 in November. Because the total

vehicle volume has increased while the HOV volumes and occupancies remained

more or less constant, the HOV contribution to both vehicle and person volume

has dropped from 2.6% to 2.0% of vehicle volume and from 24.0% to 15.9% of

person volume. The overall vehicle occupancy rate declined from 1.6 to 1.4

persons per vehicle with the HOV occupancy rate staying close to 15 persons

per vehicle in the morning peak period.

46

Afternoon peak period vehicle volume exhibited the same pattern of

fluctuations found in the Gulf and Katy vehicle volumes. Starting at 13,100

vehicles in June, it dropped to 10,700 vehicles in August and then rose again

to 13,900 vehicles in November. The person volume fo1 lowed the same pattern

with a va 11 ey of 18,200 persons and a peak of 21,700 persons. Contributing

to only 3% of the vehicle volume, HOVis comprized 14% and 21% of the person

vo 1 ume on the North Freeway. Overa 11 occupancy 1 eve 1 s have vari ed from 1.5

to 1.7 persons per vehicle in the afternoon peak period with the HOV average

occupancy hovering around 10 persons per vehicle in the afternoon peak

period. Discrepancies between morning and evening occupancy rates may be

attributed to the subjective nature of the surveying techniques with regards

to vehicle occupancy rates.

ContpafLow VoLumes

The Houston contraf1ow lane (CFL) operates from 6:00 to 8:30 in the

morning and from 4:00 to 6:30 in the afternoon. Since these time periods do

not exactly coincide with the Texas Transportation Institute (TTl) count

times, it has been necessary to obtain CFL volumes and occupancy levels from

the Houston Metropolitan Transit Authority (&.). The vehicle volumes and

classifications (i.e. van or bus) were obtained by matching up output from

mechanical vehicle count devices and actual bus schedules. The occupancy

levels were derived from actual head counts by the bus operators and by

quarter 1y spot checks of vanpoo 1 occupanc i es. In the instances where Metro

has had only daily figures, these volumes were halved based upon the assump

tion that morning and afternoon HOV volumes tend to be very similar. People

going downtown by bus or vanpoo1 in the morning usua 11y return by the same

mode in the afternoon.

47

CFL total vehicle volumes have remained fairly constant through June,

August and November. Never exceeding 500 vehicl es in the peak period, the

CFL carried between 7600 and 8100 persons per peak period. These volumes are

based upon CFL operating periods (6:00-8:30 a.m. and 4:00-6:30 p.m.). De

spite the decl ine in vehicle volumes in August, the person movement has

continued to grow in all three months. Overall occupancy levels have stayed

close to 16 and 17 persons per vehicle. Bus occupancies appear to be drop

ping sl ightly from 37 to 34 persons per bus while vanpool occupancy has

increased from 8.7 to 9.0 persons per vanpool. Although growth in CFL

volumes have been stable for some time, continued increase is anticipated

with further economic recovery.

48

SUMMARY

Projection of Findings

The project, to date, as presented in this prel iminary report, encom

passes the establishment of a study design and data collection methodology.

Primarily, only "before" operational data has been actually obtained in the

Gulf and North Freeway Corridors, and "during construction" information

collected in the Katy Freeway Corridor. No comparative analyses may be made

at this time. However, estimated projections of the operational effects of

the implementation of a transitway within one of the study corridors is

poss i b 1 e.

Use by High Occupancy Vehicles (HOVs) and corresponding passenger

throughput in HOV vehicles is expected to increase to 400 vehicles and 6,500

passengers. Likewise, percentage of total freeway passenger demand served by

HOVs will increase from about 5% to 35%. It is not known whether the extent

of modal shift to the transitway from the freeway main lanes will be signifi

cant enough to dramatically enhance freeway operations since this may be

negated by growth, latent demand, and diversion of traffic. However, this

effect, if present will be noted.

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REFERENCES

1. T r a f f i c Vol u me D a t a , S tat e De par t men t 0 f Hi g h w ay san d Pub 1 i c Transportation, Urban Planning, Houston, Texas, 1982.

2. "Proposed Dedicated Trans itway for 1-10 Katy Freeway-Project Ov erv iew, II Metropolitan Transit Authority, Harris County, Houston, Texas, September, 1982.

3. "Proposed Dedicated Trans itway for 1-45 North Freeway-Project Overv iew, II Metropo 1 itan Transit Authority, Harris County, Houston, Texas, March, 1983.

4. "Proposed Dedicated Transitway for 1-45 Gulf Freeway-Project Overview," Metropolitan Transit Authority, Harris County, Houston, Texas, June, 1982.

5. App 1 i ed Linear Stat i st i ca 1 Mode 1 s, John Neter and Wi 11 i am, Wasserman, 1974.

6. Metropo 1 itan Trans it Authority, unpub 1 i shed survey data furni shed by Bin Kang, January, 1984.

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