Travel Behavior

Strategizing Equitable Transit Evacuations: A Data-driven Reinforcement Learning Approach

Tang, Fang
Wang, Han
Maria Laura Delle Monache
2025

As natural disasters become increasingly frequent, the need for efficient and equitable evacuation planning has become more critical. This paper proposes a data-driven, reinforcement learning (RL)-based framework to optimize public transit operations for bus-based evacuations in transportation networks with an emphasis on improving both efficiency and equity. We model the evacuation problem as a Markov Decision Process (MDP) solved by RL, using real-time transit data from General Transit Feed Specification (GTFS) and transportation networks extracted from OpenStreetMap (OSM). The RL agent...

A Method for Design and Specification of Longitudinal Controllers for Vehicle Automation

Godbole, Datta N.
Raja Sengupta
1998

Within the context of advanced vehicle control systems, the authors present a general methodology for the design and evaluation of vehicle safety systems. The safety of a vehicle automation system is characterized by the operating region and capabilities of the controller, and the disturbance generating capabilities of the traffic and roadway. The authors illustrate the methodology with reference to a vehicle following scenario. Different information structures are compared by analyzing their effect on safety and system capacity

Breaking the Highway Capacity Barrier: Adaptive Cruise Control-Based Concept

Godbole, Datta N.
Kourjanskaia, Natalia
Raja Sengupta
Zandonadi, Marco
1999

A single-lane advanced vehicle-highway concept that can increase driving comfort and highway capacity is proposed. The concept can be implemented in the near future as it uses the adaptive cruise control (ACC) technology on vehicles and the intelligent ramp metering technologies on the roadway. A simulation-based performance evaluation of single-lane ACC systems under different traffic conditions is presented. The results indicate that drivers can fully use ACC systems even in stop-and-go-traffic, thereby reducing driving stress. It is also shown that ACC-equipped vehicles can maintain a...

Medium Access Control Protocol Design for Vehicle-Vehicle Safety Messages

Xu, Qing
Mak, Tony
Ko, Jeff
Raja Sengupta
2005

We propose a Medium Access Control (MAC) protocol design for a vehicle to send safety messages to other vehicles. We develop a QoS model for safety messages consistent with the active safety systems literature. Each message has a range and useful lifetime. The QoS target is to have each message be received with high probability within its specified lifetime by each vehicle within its specified range. The protocol design is based on rapidly re-broadcasting each message multiple times within its lifetime in combination with the 802.11 DCF. This makes the design compatible with the emerging...

Lower and Upper Bounds for a Symmetric Multiple Depot, Multiple Travelling Salesman Problem

Rathinam, Sivakumar
Raja Sengupta
2006

This paper extends the well known Held-Karp's lower bound available for a single Travelling Salesman Problem to the multiple depot case. The LP-relaxation of a symmetric multiple vehicle, multiple depot problem is shown to be lower bounded by an infinite family of bounds. Each lower bound can be computed in a tractable way using a matroid intersection algorithm. When the costs of travelling between any two locations satisfy triangle inequality, it is shown that there exists a 2-approximation algorithm for solving the multiple depot, multiple TSP. These results are useful in solving the...

Sensor Deployment, Self-Organization, and Localization

Sabbineni, Harshavardhan
Chakrabarty, Krishnendu
Ji, Xiang
Zha, Hongyuan
Lee, Duke
Varaiya, Pravin
Raja Sengupta
Onur, Ertan
Ersoy, Cem
Deliç, Hakan
2006

This chapter contains sections titled: Introduction SCARE: A Scalable Self-Configuration and Adaptive Reconfiguration Scheme for Dense Sensor Networks Robust Sensor Positioning in Wireless Ad Hoc Sensor Networks Trigonometric k Clustering (TKC) for Censored Distance Estimation Sensing Coverage and Breach Paths in Surveillance Wireless Sensor Networks References

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

Rathinam, Sivakumar
Raja Sengupta
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...

Dependence of Cooperative Vehicle System Performance on Market Penetration

Shladover, Steven E.
Polatkan, Gungor
Raja Sengupta
VanderWerf, Joel
Ergen, Mustafa
Bougler, Benedicte
2007

Cooperative vehicle systems (CVS) can provide intelligent transportation systems services such as probe vehicle information and hazard warnings by exchanging data among suitably equipped vehicles as they travel. The sensitivity of the performance of CVS to the market penetration of suitably equipped vehicles is explained by using Monte Carlo analyses and simulations of wireless message propagation. The CVS functions are implemented by using wireless vehicle-vehicle data communications, which can be successful only when other equipped vehicles exist within wireless range to receive the...

Approximation Algorithm for a Generalized, Multiple Depot, Hamiltonian Path Problem

Rathinam, Sivakumar
Raja Sengupta
2007

We consider a Generalized, Multiple Depot Hamiltonian Path Problem (GMDHPP) and show that it has an algorithm with an approximation ratio of 3/2 if the costs are symmetric and satisfy the triangle inequality. This improves on the 2-approximation algorithm already available for the same.

Adaptive Communication Scheme for Cooperative Active Safety System

Rezaei, Shahram
Raja Sengupta
Krishnan, Hariharan
Guan, Xu
2008

This paper presents an adaptive communication scheme for Cooperative Active Safety System (CASS). CASS uses information communicated from neighboring vehicles via wireless communication in order to actively evaluate driving situations and provide warnings or other forms of assistance to drivers. In CASS, vehicles are equipped with a GPS receiver, a Dedicated Short Range Communications (DSRC) transceiver, and in-vehicle sensors. The information exchanges between vehicles include position, speed, heading, and other vehicle kinematic and dynamic information, and the information is broadcast...