Traffic Conditions - From Now Until Forever

Traffic Conditions: From Now Until ForeverTAC 2015 | v1.0 | September 2015

TRAFFIC CONDITIONS

FROM NOW UNTIL FOREVER

SESSION : GOODS MOVEMENT - REACHING

DESTINATIONS SAFELY AND EFFICIENTLY

September 2015

1

WSP Canada Inc.

1600, boulevard René-Lévesque Ouest, 16th floor

Phone : 514-340-0046 | Fax : 514-340-1337

www.wspgroup.com


Team2

Prepared by

François Bélisle, Eng., B. Sc., M.A.

Marilyne Brosseau, Eng., M.Eng.

Steve Careau, Eng.

Philippe Mytofir, techn.

Validated by:

Stephan Kellner, Eng., M.Eng.


Presentation outline3

1. Introduction and Context

2. Basic Data

3. Methodology

4. Results

1. Road works between 2018 et 2043

2. Traffic Indexes Calibration 2014, AM and PM

3. Example of simulations

5. Conclusion


1. Introduction and Context4

A client is planning major changes to his distribution chain in an urban

area

This distributor will build a new distribution center and wishes to analyze

the best available position to minimize truck travel times

The analysis period is long, for example until 2043 (e.g. : forever)

To this end, the traffic engineer must:

Analyze and predict future road works and their impacts on the network

Analyse future truck travel times



Specific challenges awaits the traffic engineer for this study:

- Little or no transportation data, for now or for the future

- Limited access to a regional model, actual or future

- Uncertain knowledge of the future

- Tight delays

- Restricted budget

- The result of the study will have a major impact on a decision worth

millions of dollars



WSP has build a simplified regional model that can:

Simulate network loss of capacity

Evaluate the impact of congestion

Evaluate travel time for specific OD pairs

Evaluate the location that minimizes truck travel times for a given OD

matrix


2. Data – Delivery points

7

A trucking network must be identified, with origins and destinations


2. Data Number of trucks per destination

8

For each distribution center scenario, we must identify the number of

weekly trips to specific destinations in our network


2. Data – Flows (Ministère des transports du Qc)Average Annual Daily Traffic (AADT) by network section

9


2. Data – Google Maps10


3. Methodology11

1 : Which road works and how to quantify their impacts ?

2 : How to measure travel times or time « indexes »


3.1 Methodology – Road works12

Road works projects can be gleaned from a number of government sources:

Transportation Ministry

Treasury Boards

Cities

Transportation planning agencies

Road works impacts can be loosely quantify by the specialized engineers :


3.2 Methodology – 2 Travel Times 13

2 : How to evaluate travel times up to 2043:

This aspect of the methodology is divided in three parts:

a) Where to distribute car flows in space and in time

b) How to quantify the delay induced by the road works

c) How to evaluate travel times for trucks


3.2 Methodology – 2 – Traffic Flows14

The 2012 AADT flows are taken as the basis for analysis for the whole

period

Assumptions must be made to complete the holes in the data


3.2 Methodology – 2 – a – Traffic Flows in space

15

A simplified model of the region was built using a graph representing the

superior network

In this network, all destinations are nodes (but not all nodes are

destinations, representing interchanges)

A-25 Legend :

• Graph Nodes


3.2 Methodology – 2 – a – Traffic Flows in time

16

Since no regional model is typically accessible, today’s flows will be

considered constant throughout the analysis period.

Hence, only the road works impact’s will be evaluated

This corresponds to a « Jules-Verne » prediction


3.2 Methodology – 2 – a – Traffic Flows in time

17

Flows must also be analyzed in time during the day. For this, we project

AADT with a distribution function, obtained by counts on a subset of sections

of the network

Peak direction AM Peak direction PM

A network section can have either profiles or both at the same time

Time of day

Pe

rce

nta

ge

of A

AD

T

Time of day


3.2 Methodology – 2 – a – Traffic Flows in time and space

18

Road works changes drivers habits in both space and time, depending

on the importance of the construction and delays that they cause

Reassignment of trips is possible when there is capacity, either on a

different link or at another time

During peak periods, most links are saturated in a given direction, limiting

potential gains of different route choices

Because drivers won’t really gain time by going elsewhere, they can

« beat the traffic » by leaving earlier or later on the same route choice

Hence, in WSP’s simplified model, flows are not reassigned in space but

in time over a « stretched » peak period


3.2 Methodology – 2 – b - Road works delay19

A function developed by the MTQ1 is used to estimate delay:

𝑃𝑆 𝑉 = 𝑇0 +𝑇𝑆 − 𝑇0

1 +𝑉𝐶

−𝜏

où:PS(V) : Delay (min/km), depending on flow V (veh/h)

T0 : free flow delay (min/km)

TS : maximum delay in saturated conditions (min/km)

C : Capacity (veh/h)

τ : road type parameter

The parameters used were recommended for the greater Montreal region

Road works impact both the flow V and the capacity C

From delay values, we can calculate travel times

1. TREMBLAY, Pierre et BABIN, André. Experimentation of "S-curve" type Volume/Delay Functions fot the Montréal Region, Montréal,

Presentation Notes for the 9th Emme/2 Users’ Conference, Transports Québec, 1994, 41p.

Road TypeFreeFlow speed

(km/h)

Capacity

(veh/h)

T0

(min/km)

Ts

(min/km)

Highway 100 2000 0,6 10 8

Urbain highway 75 1900 0,8 10 6

Arterial Bridge 35 1450 1,75 10 7

Artère 40 1500 1,5 10 6


3.2 Methodology – 2 – c –Truck Travel Times20

Truck data trips are distributed during a typical workday between 6h00

and 18h00

For each horizon between 2018 and 2043 and for each hour of a typical

workday, trucks choose the fastest path from their origin to their

destination, given the delay on the links of the network at a given time

The sum of all travel times gives a measure of performance for a given

distribution center


3.2 Methodology – 2 – Limitations21

The model can’t predict travel times with precision

It can however discriminate one distribution center over another


Projet d'infrastructure

Probabilité

de

construction 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043

Transformation Autoroute

Bonaventure 100%

Réfection échangeur

A20/A30 100%

Réfection échangeur St-

Pierre 100%

Réfection échangeur

Turcot 100%

Construction nouveau pont

Champlain 100%

Échangeur Dorval 100%

Prolongement A19 60%

Réfection A40 100%

Réfection pont Honoré-

Mercier 100%

Réfection Louis-Hyppolyte-

La Fontaine 100%

Notre-Dame 40%

Réfonction du pont de l'île-

aux-Tourtes 100%

Élargissement A10 60%

Élargissement A30 80%

Parachèvement A20 90%

Travaux à court terme

Travaux à moyen terme

Travaux à long terme

Modifications suite aux travaux

90% de la capacité actuelle

75% de la capacité

actuelle

75% de la

capacité actuelle


+50% de la capacité actuelle



+33% de la capacité

actuelle




67% de la capacité actuelle en pointe

33% en hors-pointe



100% de la

capacité




90% de la capacité

actuelle

changement du type de route: Artère urbaine

4.1 Results – Road works

Building and impacts

22


4.1 Results – Road works23


4.2 Results – Traffic IndexesMorning peak hour calibration

Calibration in 2014 was made using data from Google Maps, here for the AM peak

Green = free flow

Yellow = slowing

Red = congestion

28


4.2 Results – Traffic IndexesAfternoon peak hour calibration

Calibration in 2014 was made using data from Google Maps, here for the AM peak

Green = free flow

Yellow = slowing

Red = congestion

29


5 Simulation examplesA morning in 2018 …

30

Truck assignments leaving from two different sites :

Site 1 Site 2


7. Conclusion31

WSP has built a simplified model that estimates the impacts of congestion

on a regional road network

The model can determine a venue that minimizes truck travels time for a

given distribution matrix

Traffic Conditions - From Now Until Forever

Engineering

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