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What is commingling? Integrating demand-response and paratransit.

  •   4 min read

This TransitTech innovation can bring better service to ADA and general population riders and bring down costs for agencies. Learn the definition of commingling and the various forms it can take.

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Already familiar with the concept? Then check out our detailed guide with key considerations for each commingling model, information on how to decide if commingling is right for your paratransit service, and how to get started. Download now.

New, technology-enabled innovations in paratransit come in many shapes and sizes. Nowadays there are routing algorithms that adjust to traffic conditions and alert riders of their vehicle’s arrival, app- or web-based booking, and even same-day or on-demand service. Fundamental to all of these features is the need for operational flexibility, which enables transit agency staff to respond to traffic jams, driver call-outs, and evolving rider needs and expectations. 

One of these new solutions is known as “commingling,” or the operation of ADA paratransit service in conjunction with a non-ADA demand-response service — anything from traditional dial-a-ride to app-based microtransit — with the goal of sharing resources to improve quality of service and reduce costs.

To break things down even further, commingling usually takes one of three main forms: 

  • Commingled fleets
  • Commingled shifts
  • Commingled trips.

Read on to learn more about each of these operational modes, as well as the potential benefits for agencies offering paratransit. 

Commingled fleets

In this model, paratransit and demand-response services share the same fleet of vehicles — pretty self-explanatory. But while an individual vehicle will only operate as paratransit or demand-response during a given driver shift, the proportion of vehicles assigned to paratransit and microtransit can change depending on demand. To see this in action we can look at Green Bay, Wisconsin, where Green Bay Metro relaunched its paratransit service in March of 2020, and soon faced a new challenge in the form of declining fixed route ridership as a result of the COVID-19 pandemic. 

So, in August 2020, the agency decided to leverage its spare paratransit vehicles to launch cost-effective microtransit in place of its hardest hit bus routes. Reservationists, support agents, drivers, and mechanics are shared freely between the services and coordinate with each other through a single platform, reducing overhead for each service. The commingled fleet now delivers 98% of trips on time — a 7% improvement — and utilization has returned to pre-pandemic levels.

Commingled shifts

In this scenario, paratransit and microtransit riders are not only served by the same vehicles, but during the same driver shifts. Rides are optimized for sharing among paratransit riders and microtransit riders, but notably not between riders of different groups. This allows for greater aggregation by slotting route-compatible on-demand trips in between pre-scheduled paratransit trips. 

In Summit County, Utah, High Valley Transit (HVT) used this model when launching a brand new transit agency to replace the fixed route and paratransit services previously provided by Park City Transit. By adding a microtransit service that commingled shifts with paratransit, HVT fills system gaps while increasing utilization across the network. In fact, within three months of its May 2021 launch, ridership of the combined service rose to three times even the pre-COVID paratransit ridership and utilization improved by more than 150%. 

Successful commingling of shifts or trips requires a driver app that communicates whether an upcoming pickup is a paratransit or microtransit rider, and whether the rider has any special needs or requires boarding assistance.

Commingled trips 

And now, the holy grail of commingling — serving paratransit and general population riders in the same vehicle, at the same time. It’s a strategy deployed by the City of St. Thomas in Ontario, Canada, as part of a comprehensive network redesign. The City launched Railway City Transit on-Demand to complement redrawn fixed routes, commingled with the existing accessible parallel transit service. Riders can book available seats on vehicles already engaged in paratransit trips headed in the same direction — all while ensuring that pre-booked paratransit trips are completed on-time and with minimal time on board. 

With commingled trips in place, utilization has improved by nearly 70% and ridership has almost doubled  — reflecting increased efficiency and a return to transit after the acute phase of the COVID-19 pandemic. Importantly, parallel transit customers continue to make up two thirds of total riders, meaning that St. Thomas is fulfilling its mission to provide accessible transit while achieving efficiency gains by bringing on-demand riders into the same vehicles. 

Potential benefits of commingling

To summarize, commingling has two primary benefits: improved service experience for riders and lowered cost per trip for agencies. Let’s dig into how each of these benefits can play out, in addition to what we saw in the examples above.

Improved service experience

  • More booking flexibility with same-day, on-demand trips available through the accessible microtransit service.
  • Reduced perception and/or stigma of “separate” service with paratransit and microtransit service operating under the same brand.
  • Opportunity for travel training for microtransit and other app-based services in a familiar, low-stress environment.

Lowered cost per trip

  • Offering paratransit riders accessible microtransit trips when available at a lower cost to the agency. 
  • Optimizing the number of vehicles required for paratransit, and deploying the remaining vehicles to lower-cost microtransit.
  • Increasing overall vehicle utilization by slotting on-demand microtransit trips into available space on paratransit vehicles.
  • Combining support resources — customer support agents, reservationists, mechanics — for both services within combined management software.

Though a powerful strategy, commingling isn’t one-size-fits-all. If you’re ready to take the next step in considering if commingling is right for your service, download our in-depth guide to integrating microtransit and paratransit here or reach out to us directly here. We’re here to help. 

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