ITS Berkeley

How network structure can boost and shape the demand for bus transit

Badia, Hugo
Argote-Cabanero, Juan
2017

Conventional wisdom states that transit riders are averse to transfers and that consequently bus networks should be designed to limit their number. Probably as a result of this belief, many real bus systems try to connect as many origins and destinations as possible without transfers, so they are usually composed of long, circuitous routes with redundant overlapping sections – and the resulting bus map is hard to understand. If coverage is extensive, many routes are needed. Economics then prevents an agency from populating all routes with sufficient buses to provide attractively frequent...

The Effect of Crosswalks on Traffic Flow

Knoop,Victor L.
Daganzo, Carlos F.
2018

In urban areas and especially in inner cities, pedestrians crossing the road considerably influence the road traffic flow. For political reasons, priority could be given to pedestrians. A larger number of crossings reduces the pedestrian load per crossing and facilitates both the pedestrian flow and the car flow; the ultimate case is a “cross anywhere” scenario. Earlier work shows that the road capacity decreases with the square of the pedestrian crossing time, hence a short crossing time is desired. Crosswalks can ensure pedestrians cross orthogonally, and thus quickly, and can thereby...

A General Model of Ridesharing Services

Ouyang, Yanfeng
Daganzo, Carlos F.
2018

The paper presents a general analytic framework to model transit systems that provide door-to-door service. The model includes as special cases non-shared taxi and demand responsive transportation (DRT). In the latter we include both, paratransit services such as dial-a-ride (DAR), and the form of ridesharing (shared taxi) currently being used by crowd-sourced taxi companies like Lyft and Uber. The framework yields somewhat optimistic results because, among other things, it is deterministic and does not track vehicles across space. By virtue of its simplicity however, the framework yields...

Adaptive Offsets for Signalized Streets

Daganzo, Carlos F.
Lehe, Lewis J.
2018

This paper shows that severe congestion on streets controlled by traffic signals can be reduced by dynamically adapting the signal offsets to the prevailing density with a simple rule that keeps the signals’ green-red ratios invariant. Invariant ratios reduce a control policy’s impact on the crossing streets, so a policy can be optimized and evaluated by focusing on the street itself without the confounding factors present in networks. Designed for heavy traffic with spillovers, the proposed policies are adaptive and need little data – they only require average traffic density readings and...

Minuet: A Method to Solve Sudoku Puzzles by Hand

Daganzo, Carlos F.
2018

This paper presents a systematic method to solve difficult 9 x 9 Sudoku puzzles by hand. While computer algorithms exist to solve these puzzles, these algorithms are not good for human's to use because they involve too many steps and require too much memory. For humans, all one can find in the literature are individual tricks, which used together in ad hoc ways can be used to solve some puzzles--but not all. To the author's knowledge, a systematic procedure made up of well-defined steps that can be carried out by hand and solve all puzzles has not been devised. This paper proposes one such...

Public Transportation Systems: Principles of System Design, Operations Planning and Real-Time Control

Daganzo, Carlos F.
Ouyang, Yanfeng
2019

This unique book explains how to think systematically about public transportation through the lens of physics models. The book includes aspects of system design, resource management, operations and control. It presents both, basic theories that reveal fundamental issues, and practical recipes that can be readily used for real-world applications. The principles conveyed in this book cover not only traditional transit modes such as subways, buses and taxis but also the newer mobility services that are being enabled by advances in telematics and robotics.

Effect of Transit Signal Priority on Bus Service Reliability

Anderson, Paul
Daganzo, Carlos F.
2019

As every user knows buses tend to bunch. To alleviate this problem, transit agencies introduce slack into their schedules and then hold buses back to schedule at pre-established control points along their routes. Unfortunately, this practice retards buses and only works with low frequency systems; i.e., when the headways are long. For higher frequency systems, which effectively operate without a schedule, headway-based control strategies show promise but unfortunately, they also retard buses. To alleviate bus retardation in all its forms, transit signal priority (TSP) is commonly used....

The Minuet Method: A Summary

Daganzo, Carlos F.
2019

This brief note shows how to solve Sudoku puzzles by hand. It is targeted to the Sudoku player who can solve intermediate and hard puzzles but sometimes fails on the extremely difficult.

A General Model of Demand-Responsive Transportation Services: From Taxi to Ridesharing to Dial-A-Ride

Daganzo, Carlos F.
Ouyang, Yanfeng
2019

The paper presents a general analytic framework to model transit systems that provide door-to-door service. The model includes as special cases non-shared taxi and demand responsive transportation (DRT). In the latter we include both, paratransit services such as dial-a-ride (DAR), and the form of ridesharing (shared taxi) currently being used by crowd-sourced taxi companies like Lyft and Uber. The framework yields somewhat optimistic results because, among other things, it is deterministic and does not track vehicles across space. By virtue of its simplicity, however, the framework yields...

Effect of Transit Signal Priority on Bus Service Reliability

Anderson, Paul
Daganzo, Carlos F.
2020

As every user knows buses tend to bunch. To alleviate this problem, transit agencies introduce slack into their schedules and then hold buses back to schedule at pre-established control points along their routes. Unfortunately, this practice retards buses and only works with low frequency systems; i.e., when the headways are long. For higher frequency systems, which effectively operate without a schedule, headway-based control strategies show promise but unfortunately, they also retard buses. To alleviate bus retardation in all its forms, transit signal priority (TSP) is commonly used....