Traffic Theory

Analyzing the Structure of Informal Transit: The Evening Commute Problem

Chavis, Celeste
Daganzo, Carlos F.
2013

Through the use of a profit-maximizing continuum approximation model, this paper systematically analyzes the development and structure of informal transit systems as a function of the network, user, and modal characteristics. This study examines the evening commute problem along a linear corridor where passengers originate uniformly from a central business district and have destinations uniformly distributed along the corridor. Informal transit drivers who are profit-maximizing will be compared against the traditional case of coordinated, government service that aims to maximize the total...

The Evening Commute with Cars and Transit: Duality Results and User Equilibrium for the Combined Morning and Evening Peaks

Gonzales, Eric J.
Daganzo, Carlos F.
2013

This paper extends Vickrey's (1969) commute problem for commuters wishing to pass a bottleneck for both cars and transit that share finite road capacity. In addition to this more general framework considering two modes, the paper focuses on the evening rush, when commuters travel from work to home. Commuters choose which mode to use and when to travel in order to minimize the generalized cost of their own trips, including queueing delay and penalties for deviation from a preferred schedule of arrival and departure to and from work. The user equilibrium for the isolated morning and evening...

System Optimum and Pricing for the Day-long Commute with Distributed Demand, Autos and Transit

Daganzo, Carlos F.
2013

The day-long system optimum (SO) commute for an urban area served by auto and transit is modeled as an auto bottleneck with a capacitated transit bypass. A public agency manages the system’s capacities optimally. Commuters are identical except for the times at which they wish to complete their morning trips and start their evening trips, which are given by an arbitrary joint distribution. They value unpunctuality – their lateness or earliness relative to their wish times – with a common penalty function. They must use the same mode for both trips. Commuters are assigned personalized mode...

Singularities in Kinematic Wave and Variational Theories: Supershocks, Solution Properties and Some Exact Solution Methods

Daganzo, Carlos F.
2014

According to the duality theory of traffic flow any well-posed kinematic wave (KW) and/or variational theory (VT) problem can be solved with the same methods either on the time-space plane or the time vs vehicle number plane. To achieve this symmetry, the model parameters and the boundary data need to be expressed in a form appropriate for each plane. It turns out, however, that when boundary data that are bounded in one plane are transformed for the other, singular points with infinite density (jumps in vehicle number) sometimes arise. These singularities require a new form of weak...

Singularities in Kinematic Wave Theory: Solution Properties, Extended Methods and Duality Revisited

Daganzo, Carlos F.
2014

According to Euler–Lagrange duality principle of kinematic wave (KW) theory any well-posed initial value traffic flow problem can be solved with the same methods either on the time–space (Euler) plane or the time vs vehicle number (Lagrange) plane. To achieve this symmetry the model parameters and the boundary data need to be expressed in a form appropriate for each plane. It turns out, however, that when boundary data that are bounded in one plane are transformed for the other, singular points with infinite density sometimes arise. Duality theory indicates that solutions to these problems...

Distance-dependent Congestion Pricing for Downtown Zones

Daganzo, Carlos F.
Lehe, Lewis J.
2015

A growing literature exploits macroscopic theories of traffic to model congestion pricing policies in downtown zones. This study introduces trip length heterogeneity into this analysis and proposes a usage-based, time-varying congestion toll that alleviates congestion while prioritizing shorter trips. Unlike conventional trip-based tolls the scheme is intended to align the fees paid by drivers with the actual congestion damage they do, and to increase the toll’s benefits as a result. The scheme is intended to maximize the number of people that finish their trips close to their desired...

The Effect of Pedestrian Crossings on Traffic Flow

Knoop, V. L.
Daganzo, Carlos F.
2017

In urban areas and especially in inner cities, pedestrians crossing the road considerably influence the road traffic flow. For political (environmental) reasons, priority could be given to pedestrians. This paper studies to which extent crossing pedestrians influence the road traffic capacity. Several distances between pedestrian crossings are considered, and moreover, a non-constant intercrosswalk spacing is considered. The focus is on the distance between pedestrian crosswalks. Both effects are quantified. The results in this paper can be used to optimize the effects of giving...

Synergies of Combining Demand- and Supply-side Measures to Manage Congested Streets

Itani, Ibrahim
Cassidy, Michael J.
Daganzo, Carlos
2021

An agent-based, multichannel simulation of a downtown area reveals the impacts of both time-shifting traffic demand with congestion pricing, and supplying extra capacity by banning left turns. The downtown street network was idealized, and loosely resembles central Los Angeles. On the demand-side, prices were set based on time-of-day and distance traveled. On the supply side, left-turn maneuvers were prohibited at all intersections on the network. Although both traffic management measures reduced travel costs when used alone, the left-turn ban was much less effective than pricing. When...

How and When Cordon Metering Can Reduce Rravel Times

Doig, Jean
Daganzo, Carlos F.
Cassidy, Michael J.
2024

The paper addresses two questions regarding cordon metering that have until now gone unanswered. The first of these pertains to how and where a metered cordon ought to be placed in a city to be of greatest benefit. A simple 3-step rule is proposed that can be readily applied in real settings, and that we call the cordon layout conjecture, or CLC. Its use is shown to minimize the overall travel time inside and outside the cordon combined. The second question pertains to the conditions for which an optimally placed metered cordon can reduce said travel time relative to doing nothing. The...