Post on 14-Dec-2015
Highway Data Highway Data WorkshopWorkshopFebruary, 2010
Highway Data Services BureauHighway Data Services Bureau
New York State Department of TransportationNew York State Department of Transportation
50 Wolf Road, 3-250 Wolf Road, 3-2
Albany, New York 12232Albany, New York 12232
(518) 457-1965(518) 457-1965
Welcome back to theWelcome back to the……
THIS MORNINGTHIS MORNING
Functional Class Map ViewerFunctional Class Map Viewer Newest Data on the WebNewest Data on the Web Traffic Data Traffic Data
Analysis/ForecastingAnalysis/Forecasting– Project Level ForecastsProject Level Forecasts– Traffic Assignment ModelingTraffic Assignment Modeling– Vehicle Miles of TravelVehicle Miles of Travel
Functional Class Maps Functional Class Maps --A proposed approach for the next A proposed approach for the next updateupdate Old approachOld approach
– Static pdf imagesStatic pdf images Difficult to produceDifficult to produce Do not reflect subsequent approved changesDo not reflect subsequent approved changes
Proposed approachProposed approach– Functional Class ViewerFunctional Class Viewer
Based on an approved FC systemBased on an approved FC system Approved changes applied immediatelyApproved changes applied immediately Updated GIS files readily availableUpdated GIS files readily available
Functional Class Functional Class ViewerViewer Internet-based viewerInternet-based viewer Based on approved system as Based on approved system as
encoded in a GIS-based fileencoded in a GIS-based file Link to original approval documentLink to original approval document Revisions noted by link to approval Revisions noted by link to approval
memosmemos Revised GIS data regularly Revised GIS data regularly
distributeddistributed http://wvmoap22/fc/
Data on the WebData on the Web
Highway DataHighway Data Detailed Inventory ListingsDetailed Inventory Listings Functional Class MapsFunctional Class Maps Highway Mileage ReportHighway Mileage Report
Traffic DataTraffic Data Traffic Data ReportTraffic Data Report Hourly Traffic Volume FilesHourly Traffic Volume Files Reference and Factor FilesReference and Factor Files
Highway Data Services Highway Data Services BureauBureau
www.nysdot.gov
– A to Z Site IndexA to Z Site Index
Select “H” Select “H”
– Select “Highway Data Services Select “Highway Data Services Bureau”Bureau”
Other NYSDOT LinksOther NYSDOT Links
https://www.nysdot.gov/divisions/https://www.nysdot.gov/divisions/
policy-and-strategy/darb/dai-unit/policy-and-strategy/darb/dai-unit/ttssttss– FHWA/FTA approved Urban AreasFHWA/FTA approved Urban Areas– Census-based Urban AreasCensus-based Urban Areas– Metropolitan Planning AreasMetropolitan Planning Areas– Statewide Annual VMT since 1920Statewide Annual VMT since 1920
Other NYSDOT LinksOther NYSDOT Links
https://www.nysdot.gov/divisions/https://www.nysdot.gov/divisions/
policy-and-strategy/darb/dai-unit/policy-and-strategy/darb/dai-unit/ttssttss
Traffic Change in New York StateTraffic Change in New York State– Change in Traffic on NYS Bridges, Change in Traffic on NYS Bridges,
Thruway and Roads, January 2010Thruway and Roads, January 2010– Contains transit and other data as Contains transit and other data as
well as traffic datawell as traffic data
Other NYSDOT LinksOther NYSDOT Links
https://www.nysdot.gov/divisions/https://www.nysdot.gov/divisions/
operating/oom/transportation-operating/oom/transportation-systems/manualssystems/manuals– Qualifying and Access Highways Qualifying and Access Highways
(trucks)(trucks)– Touring Route BookTouring Route Book
https://www.nysdot.gov/divisions/https://www.nysdot.gov/divisions/
engineering/design/dqab/rmmengineering/design/dqab/rmm– Reference Marker ManualReference Marker Manual
Other NYSDOT LinksOther NYSDOT Links
https://www.nysdot.gov/main/https://www.nysdot.gov/main/bridgedatabridgedata– Bridge information (BIN, condition, location)Bridge information (BIN, condition, location)
http://gisweb2/strviewer/http://gisweb2/strviewer/– Viewer showing location of all bridges and Viewer showing location of all bridges and
culverts with condition ratings and postingsculverts with condition ratings and postings– Only available internally (Intradot)Only available internally (Intradot)
Potential RIS ViewerPotential RIS Viewer
Currently in developmentCurrently in development Hope to eventually offer via the Hope to eventually offer via the
InternetInternet Links RIS data to GIS, orthoimagery, Links RIS data to GIS, orthoimagery,
PhotologPhotolog Links from within RIS or directly Links from within RIS or directly
through viewer interfacethrough viewer interface
THIS MORNINGTHIS MORNING
Functional Class Map ViewerFunctional Class Map Viewer Newest Data on the WebNewest Data on the Web Traffic Data Traffic Data
Analysis/ForecastingAnalysis/Forecasting– Project Level ForecastsProject Level Forecasts– Traffic Assignment ModelingTraffic Assignment Modeling– Vehicle Miles of TravelVehicle Miles of Travel
An Overview of Traffic An Overview of Traffic Data Analysis & Data Analysis &
ForecastingForecasting
HDSB ForecastingHDSB Forecasting Current year estimatesCurrent year estimates
– Matrix processMatrix process– Traffic Data ForecasterTraffic Data Forecaster
HPMS HPMS – Current year estimatesCurrent year estimates– VMT estimatesVMT estimates
All based on linear regressionAll based on linear regression
US VMT Growth Since 1984US VMT Growth Since 1984
NYS VMT Growth Since 1920NYS VMT Growth Since 1920
Traffic Count DataTraffic Count DataWhat is collected
VolumeVolume Vehicle ClassificationVehicle Classification SpeedSpeed Weigh-in-MotionWeigh-in-Motion
Traffic Count StationsTraffic Count StationsWhere it is collected
COMPREHENSIVE COVERAGECOMPREHENSIVE COVERAGE State Highways/State SystemState Highways/State System National Highway System National Highway System All Other Federal Aid Eligible RoadsAll Other Federal Aid Eligible Roads
SEGMENT SPECIFICSEGMENT SPECIFIC Highway Performance Monitoring SystemHighway Performance Monitoring System NHS Intermodal ConnectorsNHS Intermodal Connectors Bridges, Railroad CrossingsBridges, Railroad Crossings Sampling of non-Federal Aid highwaysSampling of non-Federal Aid highways
County counting partnership, MPOsCounty counting partnership, MPOs
Traffic Count CoverageTraffic Count CoverageWhen it is collected
State Highways/State System – 3 yrsState Highways/State System – 3 yrs HPMS Samples – 3 yrsHPMS Samples – 3 yrs National Highway System – 3 yrsNational Highway System – 3 yrs
Including Intermodal ConnectorsIncluding Intermodal Connectors
Federal Aid eligible roads – 6 yrsFederal Aid eligible roads – 6 yrs Bridges, Railroad Crossings – 5 yrsBridges, Railroad Crossings – 5 yrs Sampling of non-Federal Aid roads – 6 yrsSampling of non-Federal Aid roads – 6 yrs Special needs – on demandSpecial needs – on demand
Traffic Count DataTraffic Count DataHow it is collected
Continuous versus short countsContinuous versus short countsContinuousContinuous
About 175 sitesAbout 175 sites Daily and other temporal patternsDaily and other temporal patterns Design hour volume factorsDesign hour volume factors
Short (coverage) countsShort (coverage) counts Large quantity at low costLarge quantity at low cost Stations covering about 30,000 Stations covering about 30,000
milesmiles
Some of the Data UsersSome of the Data UsersWhy it is collected
Internal Users of Traffic DataInternal Users of Traffic Data
Planners – MPOs, Policy & Planning Div.Planners – MPOs, Policy & Planning Div. AADT, hourly, quarter hourAADT, hourly, quarter hour CNAM, BNAM, PNAM, traffic assignment modelsCNAM, BNAM, PNAM, traffic assignment models
Designers – scope and scaleDesigners – scope and scale AADT, DHV/DDHV, % trucks, turn movesAADT, DHV/DDHV, % trucks, turn moves
Traffic Engineers – safety analysesTraffic Engineers – safety analyses Maintenance/Construction - MPOTMaintenance/Construction - MPOT
Some of the Data UsersSome of the Data UsersWhy it is collected
External UsersExternal Users
Air quality planners/researchersAir quality planners/researchers Transportation researchers - Transportation researchers - professors professors
& students, public & non-profit agencies& students, public & non-profit agencies Realtors/developersRealtors/developers LawyersLawyers Health researchersHealth researchers New York State PoliceNew York State Police
Available DataAvailable Data
AADT – Inventories, TDR, TDV, MatrixAADT – Inventories, TDR, TDV, Matrix Hourly – Interval data on InternetHourly – Interval data on Internet Class, Speed – reports on TDV, data Class, Speed – reports on TDV, data
files files on requeston request Adjustment factors – axle, “seasonal”Adjustment factors – axle, “seasonal” DHV, DDHV, K factor/d factorDHV, DDHV, K factor/d factor Vehicle Miles of TravelVehicle Miles of Travel
– HPMS estimates by FC by Urban AreaHPMS estimates by FC by Urban Area
Vehicle ClassificationsVehicle ClassificationsBased on axle spacing via speed with which tubes are crossedBased on axle spacing via speed with which tubes are crossed
1 Motorcycles1 Motorcycles 2 Passenger Cars2 Passenger Cars 3 Two axle, four tire trucks3 Two axle, four tire trucks 4 Buses4 Buses 5 Two axle, six tire5 Two axle, six tire 6-10 Single trailer, varying no. of 6-10 Single trailer, varying no. of
axlesaxles 11-13 Double trailer, varying axles11-13 Double trailer, varying axles
Vehicle ClassificationsVehicle Classifications
““Seasonal” adjustmentsSeasonal” adjustments - Monthly Variations - Monthly Variations
Use continuous counter dataUse continuous counter data
Calculate 12 monthly averages of Calculate 12 monthly averages of the daily traffic (MADT)the daily traffic (MADT)
Average 12 MADTs to get an Annual Average 12 MADTs to get an Annual Average of the Daily Traffic (AADT)Average of the Daily Traffic (AADT)
Ratio of each MADT to AADT gives Ratio of each MADT to AADT gives monthly factormonthly factor
““Seasonal” adjustmentsSeasonal” adjustments - Daily Variations - Daily Variations
Calculate using only weekdays (Mon to Fri Calculate using only weekdays (Mon to Fri noon)noon)
Calculate using only weekend trafficCalculate using only weekend traffic
Yields three sets of adjustment factorsYields three sets of adjustment factors– Full week or seven day, weekday, weekendFull week or seven day, weekday, weekend
Daily variations are “lost” in monthly Daily variations are “lost” in monthly calculationscalculations
Weekday factors most commonly usedWeekday factors most commonly used
Seven day factors show true “seasonality”Seven day factors show true “seasonality”
Factor GroupsFactor Groups Stations stratified into FG based on Stations stratified into FG based on
1980’s analyses1980’s analyses Minimal seasonality (commuter dominated)Minimal seasonality (commuter dominated) Some seasonalitySome seasonality Highly seasonalHighly seasonal
Even winter resorts show summer Even winter resorts show summer peakspeaks
Region 7 reassessment in late 1990’sRegion 7 reassessment in late 1990’s ““Flattening” of curvesFlattening” of curves NY metro area is “average” (FG = 30)NY metro area is “average” (FG = 30)
Design Hour VolumesDesign Hour Volumesand Directional Design Hour Volumesand Directional Design Hour Volumes
3030thth highest hour highest hour Used for scaling capital projectsUsed for scaling capital projects Continuous counters used to calculate Continuous counters used to calculate
DHV and DDHV factors (K and d)DHV and DDHV factors (K and d) Good for system analyses but Good for system analyses but
questionable for project levelquestionable for project level Site specific three-day high-hour Site specific three-day high-hour
versus ADT may give better project versus ADT may give better project resultsresults
Design Hour VolumesDesign Hour Volumesand Directional Design Hour Volumesand Directional Design Hour Volumes
3030thth highest hour is used as a result highest hour is used as a result of NCHRP studyof NCHRP study
Example: count station 26 0120 in Example: count station 26 0120 in UticaUtica
Highest Hour=Highest Hour= 39913991 3030thth Hour= Hour= 37803780 100100thth Hour= Hour= 36403640 200200thth Hour= Hour= 35233523
Design Hour VolumesDesign Hour VolumesK*d and K FactorsK*d and K Factors
Factor GroupFactor Group DDHVDDHV DHVDHV
3030 6.1%6.1% 10.2%10.2%
4040 6.7%6.7% 11.6%11.6%
6060 8.7%8.7% 14.2%14.2%
Vehicle Miles of TravelVehicle Miles of TravelHPMS Statewide EstimatesHPMS Statewide Estimates
Vehicle Miles of TravelVehicle Miles of TravelHPMS Urban Area EstimatesHPMS Urban Area Estimates
AIR QUALITY INPUTSTravel Speeds
Originally based on 1990 estimations of speedVehicle Miles of Travel
Should be “based on HPMS” traffic dataVehicle Classifications
Axle-based classifications collectedFuel and weight based data not field collected
Project Level Forecasts Basic techniques
Traffic Assignment Models Selected concepts & impact on forecasts
Vehicle Miles of Travel Estimates
HPMS estimates and ad hoc approaches
Design forecast needs Growth rates Using site specific traffic data
Turning movements MPT “forecasts”
Forecast parameters Historical traffic data Trend analysis Consistency with other forecasts
Constrained vs. Unconstrained Model coordination
Time frame Date of completion/opening of project Date of forecast life (design life) of project Complex projects may include multiple
Time frame Date of completion/opening of project Date of forecast life (design life) of project Complex projects may include multiple
Multiple forecasts No build Each build alternative
Different alternatives may result in differing forecast parameters
Time Frame Build/no-build forecasts % Trucks Awareness of design thresholds
Mainline Turn lane
Awareness of generators/constraints
Most typical forecasting approach Simple or compound
Simple: AADT x [1+(rate x # yrs)] Compound: AADT x (1+rate)exp[# yrs] Past patterns indicate Simple is most
realistic Generic or site-specific rates Rural Forecasting Method
Nathan Erlbaum, 457-2967
Very common is to assume 1 or 2% Trend line from specific station/stations Growth rates from Matrix/HPMS processes
Stratified by Region and Functional Class Generate a rate using Traffic Data
Forecaster Need for rigor depends on sensitivity of
project to variations in the forecasts
Growth rate of 1% per yearMatrix growth of 1.37%
Forecast ranges from ~31,000 to ~46,000 DDHV at 6% ranges from ~1600 to ~2800 Capacity for a multi-lane urban arterial is
about 800 vehicles/lane/hour2 lanes ~1600 3 lanes ~2400 4 lanes ~3200
This forecast could yield a need for a four, six, or eight lane arterial based on the assumptions
Which forecast do you use? ANSWER:
Use Your Professional Judgment
Use appropriate sites for source data
More data is better for trending Continuous count data is best
Generic DHV, DDHV factors used as default
Prefer site specific estimates of DHV, even with short counts
7-8 8-9 9-10 10-11
11-12
12-1 1-2 2-3 3-4 4-5 5-6 6-7 ADT
1343
1527
1086
1104
1227
1396
1413
1417
1730
1735
1712
1231
21895
644 734 626 644 787 756 743 782 901 1139
926 62011766
1987
2261
1712
1748
2014
2152
2156
2199
2631
2874
2638
1851
33661DHV factor 2874 / 33661 = 8.5%DDHV factor 1735 / 33661 = 5.1%Dir Split 1735 / 2874 = 60/40
AADT 30,050DHV 8.5% x 30050 = 2600 DDHV 5.1% x 30050 = 1530
Estimate of DDHV using generic 6%: 30,050 x 0.06 = 1800
Estimate of DDHV using short count high hour: 30,050 x 0.05 = 1500
Arterial capacity ~800/lane/hour Two lanes = 1600/hour
Capacity is a threshold value of concern
Factor Group 30, generic DDHV factor - 6%
High Hour/ADT factor from short count-5.1%
30th highest hr from adjacent cc site-5.2%
Needed data for Route 17 and a connecting County Road for the I-86 project Designers questioned the AADTs
Found continuous count stations on Route 17 near the project area
Used Monthly adjustment patterns from three local cc stations to adjust the ADT from Route 17 and CR counts to a new AADT estimate
Jan Feb Mar
April
May
June
July Aug
Sept
Oct Nov
Dec
FG40 0.8 0.8 0.9 0.9 1.1 1.1 1.2 1.2 1.1 1.0 0.9 0.8Avg 0.8 0.9 0.9 1.1 1.2 1.2 1.5 1.5 1.2 1.2 1.2 0.99631 0.8 0.9 0.9 1.1 1.3 1.2 1.5 1.6 1.3 1.2 1.3 0.99632 0.8 0.8 0.9 1.0 1.1 1.1 1.4 1.4 1.1 1.1 1.0 0.9
Not easy to project Use same proportions as in existing turn
count If 5% of traffic turns left today, assume 5%
left turns in future ….if it makes sense! Known growth patterns Known restrictions
May need alternative methods Trip generation, “professional judgment”
Maintenance and Protection of Traffic Require much more site & date specificity Require construction year estimates May need per lane volumes Required to determine volumes for
Detours Number of lanes Time of day for restrictions
Traffic Assignment Traffic Assignment ModelingModeling
Four Step ProcessFour Step Process Trip GenerationTrip Generation Trip DistributionTrip Distribution Mode ChoiceMode Choice Route AssignmentRoute Assignment
Traffic Assignment Traffic Assignment ModelingModeling Daily vs peak period modelingDaily vs peak period modeling Productions/attractionsProductions/attractions
ProductionsProductionsAttractionsAttractions
– AMAM HomeHome Work placeWork place– NoonNoon Home/workHome/work
Restaurants/shopsRestaurants/shops– PMPM Work/shopsWork/shops HomeHome
Trip GenerationTrip Generation
Productions/attractionsProductions/attractions– Census dataCensus data– Land use dataLand use data
““Trip Generation, 8th Edition: An Trip Generation, 8th Edition: An ITE Informational Report “ITE Informational Report “
Traffic Analysis ZonesTraffic Analysis Zones
Productions/attractions “loaded” Productions/attractions “loaded” at centroid of TAZsat centroid of TAZs
Centroids connected to networkCentroids connected to network Familiarity with TAZ structure and Familiarity with TAZ structure and
linkages could be critical to linkages could be critical to evaluation of model outputevaluation of model output
Traffic Analysis ZonesTraffic Analysis Zonesand Census Tractsand Census Tracts
Traffic Analysis ZoneTraffic Analysis Zone– Should focus around highwaysShould focus around highways
Census Blocks & TractsCensus Blocks & Tracts– Focus on boundaries of convenienceFocus on boundaries of convenience
Center of streetsCenter of streets RR linesRR lines Visible demarcationsVisible demarcations
Loading the NetworkLoading the Network
All or nothingAll or nothing Pre-loadPre-load IterativeIterative Constrained vs. unconstrainedConstrained vs. unconstrained
Calibration & Calibration & ImpedancesImpedances Calibrating to existing dataCalibrating to existing data ““Friction” based on attributesFriction” based on attributes
– Real or artificial impedancesReal or artificial impedances FFactors actors UUsed to sed to DDecrease ecrease GGaps in aps in
EEstimationstimation– Differences and RatiosDifferences and Ratios
NOCoTSNOCoTS New bridgeNew bridge
Use of Model OutputUse of Model Output
FHWA course – 5 full daysFHWA course – 5 full days Most useful for relative comparisonsMost useful for relative comparisons
– Between forecast yearsBetween forecast years– Between alternativesBetween alternatives– Between various pathsBetween various paths
Provides another tool in forecastingProvides another tool in forecasting Best use as systems analysis toolBest use as systems analysis tool
Vehicle Miles of Vehicle Miles of TravelTravel--HPMS VMT estimates--Air quality VMT estimates--Developing ad hoc estimates
What is it?
VMT = annual Vehicle Miles of Travel DVMT = Daily Vehicle Miles of Travel Sometimes seen as VDT (Vehicle Distance of
Travel) to make it unit neutral
It is an additive measure of cumulative travelAADT and other measures are actually rates
which are time and location dependent Use of VMT eliminates that dependency
VMT Estimation
VMT = AADT x segment lengthCan be calculated for State System where
traffic counts are relatively comprehensiveEstimated for non-State Federal aid eligible
highways within HPMS using Sample expansion
Stratified by Urban, Rural, Small Urban areas
VMT Accuracy
Within HPMS, accuracy is affected by Sample “adequacy” and quality of “current year estimates” of AADT
Local VMT is more challenging given the difficulty of measuring both baseline traffic and growth
HPMS Sample Domains
Rural – 406 Samples statewide Small Urban – 395 Samples statewide Urbanized – # Samples for each area:
345 New York 76 Elmira
218 Buffalo 201 Poughkeepsie/Newburgh
195 Rochester 60 Glens Falls
208 Albany 43 Ithaca
172 Syracuse 45 Kingston
152 Utica 37 Saratoga Springs
136 Binghamton
Stratification
By Volume Group By Functional Class
Albany Urban Area – 208 Samples
FC Samples
11 44
12 23
14 47
16 41
17 53
VMT Estimation
AADT x length to calculate VMT for Samples
For each Sample Domain / FC / Volume Group, Expansion Factor =
Total length / Sample length VMT Estimate = Sample VMT x Exp Factor Sum VMT Estimates
HPMS VMT Estimation
Entire VMT estimation for Federal Aid roads is based on Sample data (all other traffic counts ignored)
Non-Federal Aid VMT (FC 08, 09, 19) based on adjustment of prior year VMT estimate
HPMS VMT Estimation
Used to be based on adjustments to meet a statewide total VMT estimate
Changed to Sample expansion with assignment of residual then adjustment of residual
Will be changed to full calculation of Federal Aid VMT … if we have the counts
Vehicle Miles of TravelVehicle Miles of Travel
Vehicle Miles of TravelVehicle Miles of Travel
HPMS VMT Estimation
Based on Current Year Estimates Current Year Estimates derived from
Matrix process Matrix process is a 15 year straight line
regression analysis Does not reflect short term changes, but
should it? Depends on purpose
AIR QUALITY INPUTSTravel Speeds
Originally based on 1990 estimations of speed
Vehicle Miles of TravelVehicle Miles of TravelShould be “based on HPMS” traffic dataShould be “based on HPMS” traffic data
Vehicle ClassificationsAxle-based classifications collectedFuel and weight based data not field collected
AIR QUALITY INPUTSTraffic data HPMS VMT estimatesGlobal Insight model output
Time series models using HPMS VMT and socio-demographics to produce urban area forecasts
National Household Travel Survey (NHTS)Estimates of VMT and urban area trip ratesSurveys conducted in 1995, 2001, 2009
AIR QUALITY INPUTSContacts
Nathan Erlbaum, System Performance & Asset Management Bureau 518-457-2967, NErlbaum@dot.state.ny.us
Patrick Lentlie, Office of the Environment518-457-0212, Plentlie@dot.state.ny.us
Uses of VMT Estimates
Planners for estimation of future growth in traffic and in economy
FHWA for funding allocationsNational Highway Traffic Safety Admin for
safety funding allocationsNYSDOT internally for funding distributionsOutside groups to estimate air quality, health,
economic, and travel impacts
Uses of VMT Estimates
Some of these uses require different stratifications than those produced via HPMS
No other “official” VMT estimates are produced by NYSDOT (except those required for Air Quality)
Ad Hoc Estimates of VMT
Requires: All available AADT data Length of system counted Total length of system
Source: Inventory spreadsheets on Internet Other HDSB resources
Highly dependent on stratification for expansion
Example – FC 16, Albany County
Expand with no stratification: Total Mileage – 114 Mileage with AADT – 58 VMT on counted roads – 580,139
580,139 x 114/58 = 1,142,874 VMT
7.6 miles contain HPMS Samples
Example – FC 16, Albany County
Expand stratified by Muni Type:
Unstratified Cities Towns Villages Total
Total Miles 113.9 46.6 60.0 7.4 113.9
Miles counted 57.8 14.9 37.4 5.5 57.8
VMT counted 580,139 135,186 380,244 64,709 580,139
Exp Factor 1.97 3.13 1.60 1.35 --
Expanded VMT 1,142,874 423,132 228,146 87,357 738,635
Stratification
Note: HPMS stratifies by Volume Group which I did not do here
Stratifying by Muni Type illustrates the variability in estimation approach
Similarly, stratification by Functional Class has been shown to yield large variations
Including Volume Group stratification seems to be the best approach
Recommendations
Stratify by several different parameters to see if converge
Include Volume Group as one of the stratification parameters
Check stratification by various parameters against HPMS values for the same Sample domains
Use professional judgment