Many proposals for extending mobility focus on creating technologies for more flexible operation of transportation. This overlooks the transformative benefits of something more fundamental: improving the design and planning of public transit networks. Rather than introducing potentially expensive and unpredictable new operational technology, this solution improves mobility by introducing Guided and Automatic Route Planning Software that will give transit planners the ability to reimagine Miami-Dade County's public transportation network in a way that will provide the flexibility that people demand.
People make journeys to fulfill a broad variety of needs. These needs may arise suddenly: an individual may need to immediately go to an urgent care clinic at any time of day or night. The origins and destinations associated with these trips may be difficult for those planning transit networks to anticipate: a family in one residential neighborhood may need to travel to another to drop off children at a babysitter. For a person who owns a car, or can afford to regularly use ride hailing services, these spontaneous trips are not burdensome. For those who do not use these means of transportation, whether due to financial constraint or a desire to reduce the congestion, accidents, and pollution inherent to them, making these trips on public transit can be quite difficult.
Many assume that fixed-route transit service cannot enable this model of transit use. This assumption fails to recognize that transit networks have merely not been measured, and thus planned, on this basis. This has had deleterious consequences; many transit agencies have seen losses in ridership since ride hailing apps have become pervasive. Miami-Dade Transit has been no exception to this trend. To fix this problem, planners must be given access to software tools that allow them to redesign their fixed-route transit system to meet the spontaneous needs of their present and future customers. Within the six month challenge period, this software will be used to generate a cost-neutral plan to restructure Miami-Dade Transit's Metrobus service. It will achieve this by evaluating modifications made by both human planners and artificial intelligence systems, resulting in a transit network that better meets the needs and values of Miami-Dade County's residents.
Typically, a transit agency's planners make changes to transit routes periodically. Often, historic, aggregated ridership data is used to justify these decisions. Routes that are overcrowded are candidates for increasing frequency; those rarely ridden may be eliminated. New service may be introduced if there is speculation that a route between two endpoints would be well-used.
Because this evaluation method focuses so heavily on areas of high demand and times of heavy commuting, it largely neglects the plight of an individual taking an unplanned, unanticipated trip. The popularity of car ownership and ride hailing services, however, indicates that people demand the ability to behave spontaneously. Thus, a transit network that will regain riders lost to these methods must be first measured and then redesigned to maximize its capability for enabling spontaneity. The methodology behind this proposal focuses on measuring precisely that.
This capability is calculated with a measurement called Spontaneous Accessibility. In this measurement, the service area of a transit agency is divided into a tightly-spaced grid of sectors. For every minute of a day, the software determines which sectors can be reached within a given time, using each of the same sectors as starting points. It does this using real transit schedules and accurate walking routes, entirely derived from public data. For each point, this results in a probability that it can be reached given the random selection of a starting point and time. The overall quality of the network is then measured by aggregating the probabilities into the final Spontaneous Accessibility score. Changes can be evaluated by instructing the program to modify the transit network, re-running the analysis, and observing the changes to the probabilities, both at the full network level and at every sector of the grid. In that way, planners and artificial intelligence systems can iteratively make alterations to transit routes and rapidly understand the Spontaneous Accessibility implications.
Spontaneous Accessibility is already been recognized as a promising new measurement for public transit planning. My paper introducing this methodology was published in the 2018 Transportation Research Record by the Transportation Research Board of the National Academies of Sciences, Engineering and Medicine, and presented at the organization's annual meeting. It was awarded the Committee on Transit Capacity and Quality of Service's best paper award as well as the Executive Committee's Fred Burggraf Award for excellence in transportation research by those 35 or younger. The work in the paper was supported by a software tool that generates Spontaneous Accessibility scores. Subsequent work has made considerable improvements to the precision and speed of the software.
Being selected by The City of Tomorrow Challenge would enable a considerable expansion of this research idea. It would enable the full-time development work that would transform the current command-line research tool into a fully-featured Guided and Automatic Route Planning Software system. This software would guide Miami-Dade Transit's planners through the restructure process by creating a web-based tool that they could use to propose and evaluate the Spontaneous Accessibility impact of transit network modifications. The automation component would use artificial intelligence to consider changes to transit routes, freeing planners from having to envision those changes. This would allow them more time to commit to maintaining awareness of the community's needs, not to mention the many challenges of operating a transit network outside of route planning. Continued development would also allow the melding of Spontaneous Accessibility measurements with demographic, civic, and commercial data. This would allow Spontaneous Accessibility improvements to be prioritized, based on areas that are significant to the community's needs.
More importantly, selection would make a connection between the motivated transportation planners of Miami-Dade County and a transit planning technology ready to emerge from the research sphere. With continuous development and agile practices, planners could begin using the software while improvements are regularly introduced. Within the six month period, it would be possible to create a proposal that restructures Metrobus service and improves Spontaneous Accessibility throughout Miami-Dade County. This would provide a powerful case study for proving the practicality of Spontaneous Accessibility evaluation as a transit planning strategy. A successful trial in Miami could mean the application of Spontaneous Accessibility measurement at transit agencies throughout the world. As a result of this challenge, a pay-per-use or subscription-based web service that planners could use to compute it would be immediately available. Not only would Miami-Dade County realize the tremendous benefit of extending better mobility options to its constituents, but out of it would emerge a compelling product capable of improving mobility throughout the world.