Traditional sidewalk performance evaluation has primarily relied on flow metrics, such as level of service, that treat pedestrians as uniform units, similar to vehicles on a highway. These methods typically rely on basic pedestrian intersection or screenline counts, which capture pedestrians at a single point location. More recently, advanced sensors such as video- and LIDAR
This project investigates how roadside LiDAR sensing and generative scene prediction models can support more informative and uncertainty-aware traffic safety assessment at urban intersections. Conventional surrogate safety measures, such as time-to-collision and post-encroachment time, are widely used to identify potential traffic conflicts. However, these measures are primarily based on observed kinematic relationships and may not
This project builds on results from prior TBD Center projects to advance the development of a multi-scale, synthetic data-based simulation framework for evaluating urban freight policy and infrastructure interventions. In Phase 1, we conducted a comprehensive review of existing freight data sources and machine learning- and generative-AI based approaches to address persistent data gaps for
Integrating Microsimulation in a Multi-scale Local Freight Activity Model Read More »
Over the last decade, many shoppers in the U.S. and around the world have quickly become reliant on home-based deliveries of household and retail goods. While growth in e-commerce is easily demonstrated from retail sales records, relevant activity trade-offs and resulting impacts on passenger and freight travel activity remain less well-understood. Some home deliveries are
Measuring the Motivators of Home Delivery Decisions Read More »
Over the past few decades, the transportation landscape has undergone a significant transformation, driven by technological innovations, demographic shifts, and evolving socio-cultural norms. The proliferation of information and communication technologies has revolutionized how and where individuals undertake daily activities, increasingly substituting physical travel with virtual alternatives and reshaping work through telework. Changes in technology have
Analysis of National Travel Trends Read More »
Longitudinal panel surveys are a cornerstone of travel behavior research, enabling measurement of behavioral change over time and facilitating before-and-after studies of policy interventions. Despite their scientific value, panel surveys suffer from a well-documented challenge: attrition. When respondents exit the panel non-randomly between different waves of longitudinal surveys, the resulting stayer sample becomes biased, thereby
Micromobility modes—including conventional bicycles, electric bicycles, electric scooters, shared micromobility services, and other emerging personal mobility devices—are becoming increasingly important components of the United States transportation system. These modes offer opportunities to support short-distance travel, improve first- and last-mile access to transit, reduce automobile dependence, and promote healthier and more sustainable travel behavior. Despite growing
Micromobility Adoption, Ownership, and Use Patterns in the United States Read More »
The rapid development of autonomous driving (also called self-driving or driverless) technologies is transforming the landscape of urban mobility. As a byproduct of autonomous vehicles, the emerging Shared Autonomous Vehicles (SAVs) are increasingly positioned at the intersection of economic viability and competitiveness, time savings and productivity, technological innovation, and transport policy. SAVs are fleet-operated, fully
The composition of the U.S. vehicle fleet is changing rapidly in response to emerging technologies, evolving consumer preferences, and shifting prices. Larger vehicles are becoming increasingly popular, with SUVs and trucks representing nearly ¾ of new vehicle sales in 2024. At the same time, consumers are choosing more fuel-efficient vehicles to reduce their operating costs.
Understanding Household Vehicle Fleet Evolution Read More »
Over the past several decades, suburbs have become home to a majority of Americans, experiencing significant growth, especially in Sun Belt metropolitan regions. Characterized by low-density land use and separated residential and commercial zones, suburban communities face substantial transportation challenges due to heavy reliance on private automobiles. This auto-dependency has led to increased congestion, safety
Understanding Transportation Investment Priorities in Suburban Communities Read More »
