Continuous Dynamic Optimization Impacts on ADA Paratransit Services: A Synthesis of Transit Practice
Continuous Dynamic Optimization (CDO) is an automated scheduling/dispatching technology designed to enhance efficiency in services like the Americans with Disabilities Act (ADA) paratransit and other demand-responsive services. Its inception was driven by the need to effectively manage unassigned trips after dispatchers' working hours and to counteract the decline in productivity and on-time performance experienced on the service day. It originally stemmed from a need to more effectively schedule unassigned trips after the dispatchers leave for the day and to address reductions in productivity and on-time performance that occur on the day of service. Given this, the objective of this study was to document the existing use of CDO for ADA paratransit services in the US. This study conducted an online survey during March 2022 to June 2022 on the practices of 11 transit agencies, which were also interviewed for the case examples. The surveyed transit agencies provided information on the state of the practice and emphasized their lessons learned and challenges.
Based on the online survey, 11 out of 24 agencies confirmed using CDO in their daily operations specifically for ADA paratransit, as some agencies either didn't use CDO or used it for other services. For this final batch of agencies, ADA paratransit services collectively used four technologies provided by different vendors and had different experiences with CDO. Technologies included traditional paratransit scheduling software used to support ADA paratransit services, and on-demand technology used to support microtransit services.
The 11 transit agencies also reflected diversity in location, size, and service model. In addition, the study also interviewed staff from several technology vendors whose CDO capabilities support ADA paratransit services. Some of the interviews led to an online demonstration of the technology.
- Consider sustainability factor when looking for a technology provider for ADA paratransit services. It is important to make sure that the technology vendor grows and keeps up with the new technology and provides the necessary future bandwidth to adequately handle the needs of the transit agency.
- Recognize how CDO parameter adjustments impact service/cost efficiency and quality. Both the agencies and technology providers highlighted the importance of understanding scheduling algorithms and parameters in detail. While experimenting with parameter settings can be laborious, it's beneficial for achieving optimal results, though vendors caution against altering multiple settings simultaneously to track which change yields specific results.
- Expect changes in staff composition and responsibilities due to the incorporation of CDO technology. Agencies surveyed in this study pointed out that the introduction of CDO may lead to functional changes, shifting dispatchers' role from proactive dispatching to addressing immediate issues not resolved by the automated CDO process. However, dispatchers are still needed for processing real-time problems such as no-show requests, incidents, accidents and breakdowns, requests for navigation assistance, and still-unscheduled trips.
- Turn off CDO if the communication system is malfunctioning. If the drivers’ communication system is down or the tablets are malfunctioning, transit agencies suggest turning off CDO immediately. Otherwise, a mismatch would occur due to the changes that the CDO is making not benefiting from the actual vehicle location or the events as performed by the driver; nor the CDO changes being communicated to the drivers’ tablets.