Peer Exchange Workshop on the "Perfect World of Measuring Congestion"
Workshop Summary Report

STEPPING STONES TO IDEAL STATE

Based on discussions throughout the workshop, seven primary themes emerged as “stepping stones” to get to the ideal state of congestion measurement for operations. These seven theme areas are:

1. Decision-making context;
2. Measure definition and calculation;
3. Customer engagement;
4. Data needs;
5. Analysis tools and methods;
6. Facility coverage; and
7. Traveler choices.

A brief discussion of each of these theme areas is included in the sections below.

1. DECISION-MAKING CONTEXT

There is a need to better understand the context in which decisions are being made and the evolving nature of these decisions. In light of this information, there is a need for transportation professionals to understand their role in the decision-making process for varied audiences (travelers, operators, planners, policy makers), and to understand that their credibility is at stake when providing information to these audiences.

There is a link between the operations decisions that can be made and the quality of the data upon which those decisions are being made. Because of this link, data availability and value is important. In some cases, there is a need for a culture change within transportation agencies to place a high value on quality data for decision-making.

2. MEASURE DEFINITION AND CALCULATION

There is a need for consistency in how the industry defines, calculates and applies congestion measures for operations. Consistency – or at a minimum clear documentation – of measure calculation steps and methods used to identify congestion thresholds is important. Transparency in reliability measure calculation and application is even more critical because reliability measures are based upon distributions rather than averages.

Related to measure definition and calculation is the need for consideration of multimodal elements in the performance measures and targets. Workshop attendees acknowledge the need for guidance on setting targets, while seeking flexibility in target-setting. Consideration of land use, accessibility and emissions impacts is important in multimodal measure definition and target-setting.

3. CUSTOMER ENGAGEMENT

There is a need to understand the best practices and tools for communicating with customers – particularly the four audiences previously mentioned (travelers, operators, planners, policy makers). Several workshop attendees expressed the importance of communication. There are different methods for communication to varied audiences, including panels, focus groups, smartphone apps, social media, etc. Likewise, the public audiences have spatially-differing community values and needs. It is important to anticipate needs of varied audiences and be proactive, while also managing expectations.

4. DATA NEEDS

There was extensive discussion by workshop attendees about data needs and needs related to data integration to improve congestion measurement for operations. A list of specific data needs was generated by attendees (see prior section of this documentation). Integration of multiple sources of data to meet decision needs is often required. There is a need for reducing the “friction” of data exchange through common application programming interfaces (APIs), segment definitions, location referencing, etc. A better understanding is needed for best practices of data use for reporting external factors (e.g., induced demand, land use change, economic activity, employment or changing demographics) to provide context and correlation with performance activities.

Within public transportation agencies, incorporating data governance and disseminating data policies is important so all users understand the data and use limitations. Workshop attendees also discussed the possibility of public-private and public-public partnerships for data acquisition when mutual gains are possible.

5. ANALYSIS TOOLS AND METHODS

There is a need for more guidance on performing before-and-after evaluations of operational treatments. More specifically, attendees were interested in better understanding when and where evaluations should be performed, the integrity of the underlying data sources, how to define the baseline for analysis, how to control for external factors, etc. Attendees discussed the concern with consistency in data sources (e.g., probe data) over time and how to handle that in before-after evaluations. There is a related need and interest in ultimately having analysis tools and methods that are integrated between the project-level, corridor-level and system-level. Attendees expressed interest in predictive analysis tools for planning and preliminary engineering purposes that incorporate external factors and can assist in target setting.

6. FACILITY COVERAGE

There is a need for better data on arterials and in rural areas to improve congestion measurement for operations. In the arterial environment, there is a pressing need for both better data, and also multimodal analysis methods. In the rural environment, there is a need for better corridor coverage where there is a focus on congestion issues. One specific difficulty is that the geographic length of traffic message channels (TMCs) used by private-sector speed providers are often many miles. Locations of localized rural congestion are therefore “washed-out” over these longer reporting segments. Rural coverage is also valuable because many rural corridors are critical for goods movement, tourism, and economic development.

7. TRAVELER CHOICES

There is a need for information about how transportation system users are using and reacting to operational treatments such as traffic information and controls. Data are needed for all system users – travelers as well as freight shippers. As an example, understanding how travelers behave or react to traffic information and controls can help transportation professionals better understand what type(s) of traffic information messaging cause a particular type of mode shift.