A person loads his bicycle onto the racks on a bus in Upper Marlboro. Image by the author.

Why don't buses come more often? Bus route designs have a big impact on that, especially when they have to serve a really wide area. Prince George’s County’s sprawling bus system is a good example of that.

In reality, TheBus, Prince George’s system, runs on time most of the time. But the county’s bus routes do reflect a decision to provide bus service to more areas of Prince George’s County overall instead of focusing on smaller and more densely populated geographic areas. And while that carries the benefit of connecting more places, it can mean lower ridership and buses that come less often.

For instance, Route 21, the bus I ride to and from work every day, connects New Carrollton, Largo, and Upper Marlboro. TheBus could maximize ridership by focusing solely on service between Largo and New Carrollton, as these are more populated areas. But connecting to Upper Marlboro is valuable because it not only provides transit service for the less dense communities between Largo and Upper Marlboro, but also provides access to the county administration offices and the county's court system, which is particularly important for people who do not or cannot drive.

This is a laudable goal - it is important to provide transit access to as many people and places as possible. But it can be problematic when people, employment centers, and destinations are spread out.

The way we design bus routes can make them slow and late (or fast and reliable)

From a transit rider’s perspective, frequency is what makes transit convenient and desirable. The higher the frequency, the less need to organize one’s day around the bus schedule. For Route 21, I'll be noticeably late if I miss a bus because I'll have to wait about 30 minutes for the next bus during the peak, or an hour at non-peak times. I plan my day expecting the bus to be on time, but I still get to the stop early so I'm certain to not miss the bus.

Frequency is a function of how many buses are used on a route at a given time (and to a greater extent, the resources available to provide transit service). Bus routes that take more time to complete, because they have circuitous routes, connect out-of-the-way destinations, or are simply long distance, require more buses to provide service at a high frequency.

And that’s the challenge in Prince George’s County. Buses cover a large geographic area, meaning there’s a high number of people who can access transit. But at the same time, many routes zig-zag and loop around, which makes each route take more time and increases the opportunity for buses to get caught in traffic. That can make it hard to transfer buses, especially if riders have to wait a long time between buses, reducing the number of places they can get to.

How could Prince George’s make bus service better?

Many of the challenges of providing service in the county are linked to the balance between geographic coverage and frequency. TheBus is doing well in regards to on-time performance, but it can explore new ways to make transit more convenient with higher frequencies.

One way to do that is by looking for ways to shorten routes. For instance, Route 21 goes a little bit out of the way to stop at the Largo Metrorail station. It could be possible to change the route to go to the Metro directly from Prince George's Community College.

The trade off, though, is that while this would shorten the route, it would also take out the stop at the Kaiser Permanente health center.

Current Route 21 alignment shown in blue. An alternative alignment would shorten the route, but also remove the health center.

Perhaps Prince George’s could also create more express routes, or routes that connect two or three major destinations without traveling too far out of the way. Route 21 already has an express route, Route 21X, which connects the Prince George's Community College with New Carrollton Metrorail.

Should Prince George’s County not want to change the routes, it could of course improve service by adding more buses. But this option might not be feasible given the costs of operating buses and paying drivers.

TheBus does a pretty good job running on-time, but that’s only one component to convenient transit. The next step is to figure out how to increase the frequency of buses.

Bryan Barnett-Woods is a transportation planner in Prince George’s County with the Maryland-National Capital Park and Planning Commission. In addition to bicycling and rowing, Bryan likes nothing more than a good walk in the city. He lives in Barney Circle with his wife and young son. The opinions expressed in this post represent Bryan’s opinions only and do not represent the opinions of his employer.