Data

Determining the Capacity Benefits of Real-Time Signal Control at Intersections

Skabardonis, Alexander
Gallagher, Brian R.
Patel, Kartik P.
2000

Traffic responsive control strategies are increasingly being implemented to improve intersection performance. Critical intersection control (CIC) is using real-time traffic data to better assign green times to conflicting movements. However, the benefits of CIC have not been assessed, and existing methodologies for estimating intersection performance do not account for CIC or other traffic responsive control strategies. The effectiveness of CIC was evaluated at seven signalized intersections in the City of Los Angeles. The findings indicate that CIC generally improves traffic operations....

Are Shelters in Place? Mapping the Distribution of Transit Amenities via a Bus-Stop Census of San Francisco

Moran, Marcel E
2022

Transit stops serve as crucial components of journeys for riders, but their condition is often left out of equity considerations. Two important empirical questions are what stop amenities, such as places to sit, clear sign age, shelters for inclement weather, and unobstructed curbs are present, and how are they distributed across systems, which may reveal neighborhood or route-specific disparities. San Francisco, CA represents an ideal case for which to pursue this question, given it maintains a ‘transit first’ policy directive that mandates public space prioritize transit over private...

Willingness of Hurricane Irma Evacuees to Share Resources: A Multi-Modeling Approach

Wong, Stephen D
Yu, Mengqiao
Kuncheria, Anu
Shaheen, Susan A
Walker, Joan L
2022

Recent technological improvements have greatly expanded the sharing economy (e.g., Airbnb, Lyft, and Uber), coinciding with growing need for transportation and sheltering resources in evacuations. To understand influencers on sharing willingness in evacuations, we employed a multi-modeling approach across four sharing scenarios using three model types: 1) four binary logit models that capture each scenario separately; 2) a multi-choice latent class choice model (LCCM) that jointly estimates multiple scenarios via latent classes; and 3) a portfolio choice model (PCM) that estimates...

Using Cooperative Adaptive Cruise Control (CACC) to Form High-Performance Vehicle Streams: Simulation Results Analysis

Liu, Hao
Kan, Xingan (David)
Shladover, Steven E.
Lu, Xiao-Yun
2018

This document contains detailed simulation results analysis and discussion for the Federal Highway Administration (FHWA) Exploratory Advanced Research (EAR) project entitled Using Cooperative Adaptive Cruise Control (CACC) to Form High-Performance Vehicle Streams. The objective of this study is to obtain authoritative predictions of traffic impacts of ACC and CACC at various market penetrations and define the CACC operation strategies that create the most capacity and throughput improvement in the freeway traffic stream. A microscopic traffic simulation environment has been developed for...

Understanding How Cities Can Link Smart Mobility Priorities Through Data

Shaheen, Susan, PhD
Martin, Elliot, PhD
Hoffman-Stapleton, Mikaela
Slowik, Peter
2018

This white paper presents a generalized evaluation framework that can be used for assessing project impacts within the context of transportation-related city projects. In support of this framework, we discuss a selection of metrics and data sources that are needed to evaluate the performance of smart city innovations. We first present a collection of projects and applications from near-term smart city concepts or actual pilot projects underway (i.e., Smart City Challenge, Federal Transit Administration (FTA) Mobility on Demand (MOD) Sandbox, and other pilot projects operating in the...

Single-Channel IVHS Communication Architecture

Linnartz, Jean-paul M. G.
1994

This report documents a single-channel architecture offering two-way communication between vehicles and a fixed communication infrastructure. Part I discusses the technical advantages and disadvantages of a dedicated Intelligent Vehicle Highway Systems (IVHS) communications infrastructure versus the use of a hybrid system involving several existing communication networks. Aspects such as spectrum efficiency, message capacity, and network performance are described. Part II proposes a network architecture that offers several transmission services essential to IVHS communications, using only...

Matroid Intersection and its Application to a Multiple Depot, Multiple TSP

Rathinam, Sivakumar
Sengupta, Raja
2006

This paper extends the Held-Karp’s lower bound available for a single Travelling Salesman Problem to the following symmetric Multiple Depot, Multiple Travelling Salesman Problem (MDMTSP): Given k salesman that start at different depts, k terminals and n destinations, the problem is to choose paths for each of the salesmen so that (1) each vehicle starts at its respective depot, visits atleast one destination and reaches any one of the terminals not visited by other vehicles, (2) each destination is visited by exactly one vehicle and (3) the cost of the paths is a minimum among all possible...

The Relative Vulnerability Index: A Framework for Evaluating Multimodal Traffic Safety

Grembek, Offer
2012

The multimodal transportation network includes a mix of inherently different modes. In addition to differences in price, range, and comfort of travel, these modes differ in mass and velocity, which correspond to different orders of magnitude in the kinetic energy carried. This discrepancy in kinetic energy affects both the level of protection of each mode, and the level of damage it can inflict on users of other modes. Unfortunately, accounting for both sides of a crash is often overlooked. While the quantities and variables of collected data continue to increase, the analyses conducted...

Reachability Analysis for FollowerStopper: Safety Analysis and Experimental Results

Chou, Fang-Chieh
Gibson, Marsalis
Bhadani, Rahul
Bayen, Alexandre M.
Sprinkle, Jonathan M.
2021

Motivated by earlier work and the developer of a new algorithm, the FollowerStopper, this article uses reachability analysis to verify the safety of the FollowerStopper algorithm, which is a controller designed for dampening stop-and-go traffic waves. With more than 1100 miles of driving data collected by our physical platform, we validate our analysis results by comparing it to human driving behaviors. The FollowerStopper controller has been demonstrated to dampen stop-and-go traffic waves at low speed, but previous analysis on its relative safety has been limited to upper and lower...

Lagrangian Sensing: Traffic Estimation with Mobile Devices

Bayen, Alexandre M.
Work, Daniel B.
2009

An inverse modeling algorithm is developed to reconstruct the state of traffic (velocity field) on highways from GPS measurements gathered from mobile phones traveling on-board vehicles. The algorithm is based on ensemble Kalman filtering (EnKF), to overcome the nonlinearity and non-differentiability of a distributed highway traffic model for velocity. The algorithm is implemented in an architecture which includes GPS enabled phones and a privacy aware data collection infrastructure based on the novel concept of virtual trip lines (a technology developed by Nokia). The data collection...