Measure how well a transit street moves people, goods, and services, considering capacity, volume, travel time, and reliability. Set multiple time periods for evaluation, such as full weekdays, weekends, and typical peak periods. Peak periods generally span several hours. Evaluating for peak 15-minute periods may lead to results prejudicial to all-day operation.
Total person movement and total person capacity are primary performance measures for transit streets that encompass the current and long-term potential of a street to serve the city.
Count transit riders, people in private motor vehicles, people walking, and people riding bicycles. Use automated counts when available for walking, bicycling, and motor vehicle traffic, combined with short manual samples of vehicle occupancy to assess total person movement. Automatic passenger counters (APCs) precisely track ridership numbers and characteristics. Measuring ridership and boardings through specific segments and corridors enables highly localized analysis of transit performance.
Use average person capacity per lane to understand the effects of a design and the number of people moved per lane, at peak times and all day, as a performance measure for motorized modes. This measure is significantly more accurate than using vehicle capacity, vehicle delay, or vehicle traffic volume alone.
Transit Travel Time
Planned trip time combines average travel time and variation to generate a single number, such as the 50th or 85th percentile travel time, reflecting a typical traveler’s experience of the mobility system. Comparing these numbers across modes for a trip along the street, or for a set of trips around the network, helps evaluate the real time saved by transit street design changes. Pedestrian travel time which is affected by the completeness of the pedestrian network and by signal timing and the distance between crossings, should be added to provide a more accurate view of total travel time.
At the network level, the planned travel time can be used to evaluate the effects of a transit street project on the performance of the system as a whole. When applied to the entire city or region in relation to demographic and employment location data, planners can evaluate the number of jobs, businesses, or other neighborhoods accessible by transit within a target travel time. The equity of the transportation system can be evaluated using this method, by comparing the level of access provided to each neighborhood.
Across modes, delay compared with free-flow movement is important for understanding the potential value of various transit priority treatments, but is less meaningful when considering personal mobility. Use delay and queuing to inform intersection-specific design treatments, such as the size of pedestrian refuge areas or upstream traffic signal management. Changes to vehicle queue length at key intersections may be relevant to the perception of a project’s impacts, and should be understood in the context of overall street operations and impacts on cross streets.
Access to the City
A primary metric for evaluating the effectiveness of a transportation system is the number of destinations—rather than the physical territory or distance—reachable by residents in set amounts of time. Applying this measure to the transit-walking system creates a master effectiveness metric that can be applied to evaluate potential large transit investments or changes in transit network structure.