Using Probe-Based Speed Data and Interactive Maps for Long-term and COVID-era Congestion Monitoring in San Francisco
Probe data that provide roadway speeds and travel times are increasingly being used for a variety of purposes in the transportation domain. A key use of these datasets has been roadway performance monitoring by state and local transportation agencies that are mandated to measure and report performance of their transportation networks. The San Francisco County Transportation Authority (SFCTA)…read the rest of the article here.
Ride-Hail Data Suppression Strategies Can Lean to Biased Outcomes
The Chicago ride-hailing data set is one of the few data sets in the United States containing details of individual ride-hail trips. To protect privacy, locations and times are aggregated, and locations are further suppressed when the frequency of trips is low. Most researchers using this data remove the trips with suppressed locations or external destinations from their analysis…read the rest of the article here.
Estimating the Uncertainty of Traffic Forecasts from their Historical Accuracy
Traffic forecasters may find value in expressing the uncertainty of their forecasts as a range of expected outcomes. Traditional methods for estimating such uncertainty windows rely on assumptions about reasonable ranges of travel demand forecasting model inputs and parameters. Rather than relying on assumptions, we demonstrate how to use empirical measures of past forecast accuracy to estimate…read the rest of the article here.
Do transportation network companies increase or decrease transit ridership? Empirical evidence from San Francisco
Transportation network companies (TNCs), such as Uber and Lyft, have been hypothesized to both complement and compete with public transit. Existing research on the topic is limited by a lack of detailed data on the timing and location of TNC trips. This study overcomes that limitation by using data scraped from the Application Programming Interfaces of two TNCs, combined with Automated Passenger…read the rest of the article here.
The Changing Accuracy of Traffic Forecasts
Researchers have improved travel demand forecasting methods in recent decades but invested relatively little to understand their accuracy. A major barrier has been the lack of necessary data. We compiled the largest known database of traffic forecast accuracy, composed of forecast traffic, post-opening counts and project attributes for 1291 road projects in the United States and Europe…read the rest of the article here.
Publications Under Review
A model of ride-hailing driver participation: Shift duration, start time, and start location.