L02 – Establishing Monitoring Programs for Travel Time Reliability SHRP 2 Joint Technical...

L02 – Establishing Monitoring Programs for Travel Time Reliability SHRP 2 Joint Technical Coordinating Committee Meeting

Irvine, CA - April 8, 2010

April 8, 2010 SHRP2 L02 2

Purpose and Deliverables

• Guidebook– Travel time reliability

monitoring system– Design, build, integrate,

operate, maintain• System prototype• Efficacy assessment

– How well the guidebook and system work

– Real-world network and data (primary)

– Simulation (if needed)


Research Team

Ralph Hessian


In the midst of other SHRP2 projects

L02 – Establishing Travel Time Monitoring

Systems

L13 – Archive for Reliability and Related Data

L11 – Evaluating Alternative Operations

Strategies to Improve Travel Time Reliability

L17 – A Framework for

Improving Travel Time Reliability

L14 – Traveler Information and

Travel Time Reliability

L05 – Incorporating Reliability

Performance Measures into the

Transportation Planning and Programming

Processes

L03 – Analytic Procedures for

Determining the Impacts of Reliability Mitigation Strategies


Guiding Principles

• Be clear and action oriented• Use field-based case studies as much as possible• Employ a long-term vision• Learn from operational agencies during

development• Focus on origin-destination travel times• Stress the use of probe vehicles• Develop clear, concise, and robust metrics

tailored for all users


Phase I - Finished

System Design Needs: Define user and functional requirements for travel time reliability monitoring systems– Task 1: Inventory and Assess Existing Traffic Monitoring

Systems– Task 2: Identify User Needs– Task 3: Characterize User Needs– Task 4: Define Functional Requirements– Task 5: Phase I Interim Report


Phase II – About to Start

System Design Completion and Guidebook Preparation

– Task 6: Develop Sampling and Data Acquisition Plans– Task 7: Design a Monitoring System– Task 8: Assess the Design Trade-offs for Real-time versus

Archived Travel Time Data Collection Systems– Task 9: Phase II Report – Including a Draft of the Guidebook


Phase III – In the Future

Validate Monitoring Programs– Task 10: Program Validation

• Subtask 10.1: Module Development• Subtask 10.2: Module Integration• Subtask 10.3: Site selection (Five sites)• Subtask 10.4: Validate Systems• Subtask 10.5: Analyze Results• Subtask 10.6: Summarize Results• Subtask 10.7: Update Guidebook

– Task 11: Final Report


Task 1 – Inventory and Assess Existing Traffic Monitoring Systems

• Findings based on the 25 largest metropolitan areas

• Nearly every major metropolitan area has travel time monitoring and reporting capabilities

• Many areas are served by several information providers, public and private

• A few providers report travel time reliability information to travelers

• Several providers contrast current travel times and delays with averages

• Behind-the-scenes data processing firms are striving to determine how to report and use travel time reliability information

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Best

Pra

cti

ce

Exam

ple

s

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Source: GMC Website

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Task 2/3 – User Needs• A few agencies are reporting reliability measures• Clearly communicating travel time reliability information is a challenge• Many agencies strive to use reliability measures in decision-making• But how they use the information varies widely:

– planning and programming, user cost assessment, performance assessment• Reliability measures are used internally to monitor and manage:

– peak hour congestion, work zones, incidents, and special events• Agencies must understand what users value and what they will listen to and

comprehend • Most common communication channels are:

– media outlets, 511, other internet tools (websites, email distribution lists, twitter) • Average travel time is reported most often and is the easiest metric to communicate• Most agencies are unsure about using private sector information• Agencies need to share information and resources to do an effective monitoring job• Communication tools need to be constantly updated to ensure user confidence

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Task 2/3 – Passenger MetricsBroad

Classification by Trip Purpose

Detailed Classification by

Trip Purpose

Importance / Severity of Reliability

Primary User I nformation Need

Recommended Reliability Measure

Daily, Constrained Trips

Work High Delay during heaviest traffic days. Planning Time Index Pick-up & Drop-off

Children High

Daily, Unconstrained Trips

Shopping Low Additional time necessary to generally arrive on time. Buffer Index

Return home High-Medium

Occasional, Constrained Trips

Appointments High Travel time during peak period versus off-peak period. Travel Time Index

Leisure Medium-Low

Occasional, Unconstrained Trips Leisure Low Additional time necessary to

generally arrive on time. Buffer Index

Source: Adapted from SHRP 2 Project L11 Technical Memorandum 1, Exhibits 2 and 4

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Freight Metrics

Source: Adapted from SHRP 2 Project L11 Technical Memorandum 1, Exhibit 3

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Category Key Questions Key Takeaway Points

Relative Amount of Information Received

1. Data Collection Practices and Travel Time Measurement Tools

Do you currently use travel time reliability as a performance measure for your system? If so, how do you measure it? Where, when, and for what facilities, areas, corridors, or OD pairs do you measure it?

What information is gathered to monitor travel time reliability?

How do you obtain travel time information?

Are the travel time reliability results archived and/or reported?

Many new and emerging data collection technologies exist, but agencies are still using inductive loops as the most common source for travel time and speed data.

Quality control and management of tools and data is very time intensive and takes more resources than most agencies have available.

Partnerships with other public and private agencies are vital when it comes to assembling the resources necessary to accurately record and archive data.

Medium

2. Communication to Users

What information is presented to the users of your system and how is it presented?

In the future, what reliability information can you envision being delivered to system users and in what forms?

Do you provide pre-trip information to users on system conditions? If so, what media is this communicated through?

A few agencies are experimenting with reporting reliability measures. Overall, most users seem more interested in knowing travel times rather than travel time variance.

Reliability measures seem to be more useful when communicating pre-trip information.

Users are demanding travel time information on alternate routes.

Providing travel time or arrival information causes users to perceive the system as reliable.

With all of the technology available, agencies need to better understand the most effective and efficient means by which to communicate reliability information.

High

3. Business Processes and Future Monitoring Plans

To what extent do you incorporate information about travel time reliability into day-to-day operations?

Do you have quantitative or qualitative goals with respect to reliability? What are the challenges you face with setting reliability goals?

Are there gaps in the travel time information you use that need filling? Are there other deficiencies that need improvement?

Using reliability measures is a goal of many agencies, but the way they are used varies. Examples are planning and programming, user cost assessments, performance assessments.

Need to develop reliability initiatives at the national level and encourage partnerships at the local level to more easily reach goals established by initiatives.

Few agencies monitor reliability on roadways other than freeways.

High

4. Performance Measures

What travel time reliability performance measures or indices do you monitor? Are these measures archived, tracked, or analyzed in any way?

Under what system conditions do you monitor travel time reliability (relating to the seven factors influencing reliability)?

What spatial and temporal levels of detail do you capture in your existing monitoring system and would you prefer more or less detail?

Understanding the “why” behind the variability is important for agencies to mitigate the problem behind the variability.

Agencies would like more guidance on evaluating performance measures on a network level.

Need to identify measures most clearly portrayed to the public and that are not facility or mode specific.

Medium

5. Education and Outreach

What resources do you most commonly use to educate your organization on travel time reliability monitoring practices?

Does your organization provide public information programs to educate users on how to use travel time reliability monitoring resources?

Do users generally feel the system is reliable and, if so, why? If not, what do you think could be implemented to change their perception?

The traveling public is intuitively aware of reliability concepts, but this intuition must be enhanced with educational tools that are marketable and easily accessible to the public.

It is important to share information among agencies to advance the research and implementation of reliability programs.

Effective outreach strategies must be centered on what users perceive and value and what they will listen to and comprehend in regard to reliability reporting.

The guidebook ought to: 1) compile best practices, 2) provide specific examples, 3) provide guidance on reporting reliability for all user types, and 4) address integration with the private sector.

Low

Task 2/3 – Key Take-Away Points

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Task 4- System Vision

Use Cases for:• Passenger travelers• Freight movers• Policy makers• Roadway system managers• Transit system managers

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Information ServiceProvider

Other Transportation Management

Systems

Transportation System Data

Collection Subsystems

Transportation Management

SystemOther


Systems


RTIP FocusArea

Traveling Public


Other Transportation Management

Systems

Transportation System Data

Collection Subsystems


SystemOther


Systems


RTIP FocusArea

Traveling Public

Dual-use: • Real-time• Off-line

RTIP Guidelines: Real-Time System Management Information Program

Real-Time System Archived Data System

Network Surveillance

Traffic Probe Surveillance

Weather Information Processing and Distribution

Maintenance and Construction Activity Coordination

ISP Based Trip Planning and Route Guidance

Broadcast Traveler Information ITS Data Warehouse

Interactive Traveler Information ITS Virtual Data Warehouse

Dynamic Route Guidance -

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Task 4 - System Capabilities• Address both person and freight trips• Support computation and estimation of travel time reliability• Support prediction algorithms for both real-time and static (e.g.

planning) applications• Impute data for facilities and areas where data are not available• Support aggregation of localized travel time reliability to corridors,

subsystems, and systems• Monitor long- and short-term changes in the reliability of roadway

systems, and compare the findings with peer systems• Be able to check for equipment failures in real-time• Be compatible with existing (legacy) systems.• Receive data from existing and future sensing technologies• Disseminate travel time reliability information to users.• Use public and private sources of data as appropriate.

April 8, 2010 SHRP2 L02 20

Task 4 – System Capabilities (cont)• Serve the traffic monitoring needs of the public and, to the

extent practical, the private sector.• Store travel time and other data concerning reliability in a

standard-compliant data base • Use appropriate telecommunication technologies

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User Type Use Case Index Use Case Description

Travelers

Constrained Trips

T1 A user wants to find out, in advance, what time to leave for a trip and what route to take in order to arrive at a destination on time.

T2 A user wants to find out, immediately before a trip, what time to leave and what route to take in order to arrive at a destination on time.

T3 A user wants to determine the time or extra time needed for a trip in order to arrive on-time a certain percentage of the time.

T4 A user wants to calculate the expected travel time and buffer time for a congestion-inducing event (as defined by the seven sources of unreliability).

T5 A user wants to determine en-route whether an alternate route would increase the likelihood of an on-time arrival or minimize the travel time.

Unconstrained Trips T6

A user wants to know what time of day to make a trip in order to generally arrive on time.

T7 A user wants to know how much extra time to add on to a trip to generally arrive on time.

Use Cases – The Building Block

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Use Case ProcessingUse Case T3: A user wants to determine the time or extra time needed for a trip in order to arrive on-time a certain percentage of the time.

Purpose: Different users making different constrained trips may have varying ideas on acceptable risks of arriving late that is not necessarily the 5 percent risk captured by the planning time metric. This capability would allow travelers to select the percentage of time that they need to arrive on-time to find the route that best accommodates this threshold. Steps:

1. User selects an origin. 2. User selects a destination. 3. User selects from a list of percentage thresholds of how often they want to

arrive on-time (example: 75%, 85%, 95%). 4. User selects the day(s) of the week. 5. User selects the time period.

Results:

A map of the route with the lowest travel time for the selected threshold. The route’s average travel time, selected percentile travel time, and buffer

time corresponding with that percentile travel time. An option to view the average travel times and percentile travel times of

alternate routes. Spatial Aggregation: Origin-Destination Pair Metrics:

Buffer Time Percentile Travel Time Average Travel Time

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Data Needs

Travel Time Input

Free

-Flo

w

Med

ian

95th

Per

cent

ile

Def

ined

Per

cent

ile

Max

imum

C

urre

nt

Ave

rage

Traveler Freight Mover

T1 T2 T3 T4 T5 T6 T6 F1 F2 F3 F4 F5 F6 F7

Tra

vel T

ime

Met

ric

Planning Time X O-D O-D R R O-D O-D O-D O-D R O-D O-D O-D Planning Time Index X X Buffer Time X X O-D R R Buffer Index X X Travel Time Index X X Average Travel Time X X O-D O-D O-D O-D R O-D O-D O-D O-D O-D Percentile Travel Time X O-D Maximum Travel Time X R Current Travel Time X R Free-Flow Travel Time X

Con

gest

ion

Sour

ce All Combined X X X X X X X X X X X X X

Incidents

X Weather X Construction

X

Special Events X Traffic Control

Fluctuations in Demand Inadequate Capacity

Example for travelers and freight movers

R= Travel Time Metric aggregated to RouteO-D = Travel Time Metric for Origin-Destination Pair

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Data Sources

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AV

I S

en

sors

in

Hou

sto

n

April 8, 2010 SHRP2 L02 26

Data Issues• Traffic data collection (infrastructure, vehicle,

private)• Other data/sources (incidents, weather, other)• Storage• Validation (infrastructure, vehicle)• Imputation• Computation • Assembly (routes, corridors, areas, etc.)• Causal analyses

– Incidents, weather, construction, special events, traffic control, fluctuations in demand, inadequate base capacity

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Report Generation

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Mon

thly

Tra

vel C

on

dit

ion

s

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System Integration

Mobile Communications

Remote Traveler Support

Traffic Management

Emergency Management

Commercial Vehicle

Administration

Maintenance & Construction Management

Transit Management

Fleet & Freight

Management

Archived Data Management

Vehicle

Emergency Vehicle

Commercial Vehicle

Transit Vehicle

Maintenance & Construction

Vehicle

Roadway

Security Monitoring

Toll Collection

Parking Management

Commercial Vehicle CheckVehicles Field

Travelers Centers

Travel Time Reliability Monitoring

Emissions Management

Toll Administration

Fixed Point-Fixed Point Communications

Information Service Provider

Personal Information

Access

Mobile Communications

Remote Traveler Support

Traffic Management

Emergency Management

Commercial Vehicle

Administration

Maintenance & Construction Management

Transit Management

Fleet & Freight

Management

Archived Data Management

Vehicle

Emergency Vehicle

Commercial Vehicle

Transit Vehicle

Maintenance & Construction

Vehicle

Roadway

Security Monitoring

Toll Collection

Parking Management

Commercial Vehicle CheckVehicles Field

Travelers Centers

Travel Time Reliability Monitoring

Emissions Management

Toll Administration

Fixed Point-Fixed Point Communications

Information Service Provider

Personal Information

Access

April 8, 2010 SHRP2 L02 32

Questions / Thank you

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