The National Academies

TCRP Synthesis J-07/Topic SB-36 [Active (Synthesis)]

Dynamic Optimization on ADA Paratransit Service
[ TCRP J-07 (Synthesis of Information Related to Transit Practices) ]

  Project Data
Funds: $45,000
Authorization to Begin Work: 5/7/2021 -- estimated
Staff Responsibility: Mariela Garcia-Colberg
Research Agency: Texas A&M Transportation Institute
Principal Investigator: Will Rodman
Completion Date: 6/10/2023
Fiscal Year: 2021

Tentative Scope




Despite decades of experience with automated scheduling for paratransit services, true batch optimization (i.e., considering all trips at once) has only advanced as systems move from paper-based schedules to app-based schedules.  Dynamic optimization requires the driver to be working with an app-based schedule that provides the driver with only one to two hours of scheduled rides at a time, thereby allowing for last-minute schedule changes. 

Several software vendors have developed different approaches to dynamic optimization, and their different versions are now being implemented by scores of transit agencies in the U.S., Canada, and elsewhere. 

There are two basic approaches to optimization -- On-Demand and Pre-Book.

On-demand is where the riders generally communicate directly with the driver through an app, and schedule optimization is limited to short-term, direct application to the available fleet on the day of service. Pre-book optimization is applied to systems with large subscription demand where the system is susceptible to significant cancellation rates, and there is minimal daily contact with the rider. These systems remove rides on late running vehicles experiencing unexpected traffic congestion, accidents, breakdowns, etc. 

The prospective benefits of dynamic dispatching include one or more of the following:

  • Improved productivity and on-time performance
  • Reduced cost of dispatch labor by reducing the number of dispatchers needed
  • More focused dispatching on immediate chores, such as no-show requests
  • A broadened and less expensive labor pool for prospective dispatchers
  • Increased efficiencies by linking ADA paratransit with microtransit services operated by ADA paratransit-certified drivers.


While these benefits are significant, the results have not been constant in all transit systems.


Synthesis Objective:

This Synthesis will document the current use of dynamic optimization in ADA paratransit, and the benefits realized, if any.  This synthesis will develop benchmarks and operational performance measures that define the experience in the industry from the perspective of transit agencies, dispatchers, drivers, and riders. This synthesis will document the ways in which transit agencies have addressed the shortcomings and challenges that have manifested themselves in the tailoring, deployment, and use of the dynamic optimization systems, including issues with technology and service delivery.

Information To Be Gathered will include specific items as determined by the panel during the first panel meeting.

Information Will Be Gathered by a literature review and a survey of transit agencies. The report will include case examples.

TRB Staff
Mariela Garcia-Colberg
Phone: 202-334-2361
Email: mgarciacolberg@nas.edu

Meeting Dates
First Panel: TBD
Teleconference with Consultant: TBD
Second Panel: TBD

Topic Panel 


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