Why MetroRapid Needs Schedules
Every public transportation line has a schedule. It tells you, roughly, when you can expect the service to pick you up and when it will arrive at your destination or transfer point.
Although we tend to think of high-frequency rail systems as “show up and go,” most of them have published timetables too.
But that’s not true of MetroRapid, Austin’s rapid bus (officially, “bus rapid transit”) system. MetroRapid has no public timetables. Instead, Capital Metro advertises the service as arriving at fixed intervals.
As opposed to traditional fixed schedules, this practice is called “headway-based scheduling,” and it’s common on very high-frequency rapid transit services. The key word being high-frequency. It makes no sense that Capital Metro is using headway-based scheduling during off-peak hours when MetroRapid only comes every 20–30 minutes.
When headway-based scheduling works (and doesn’t)
When a transit service is very frequent, headway-based scheduling offers several benefits:
- Vehicles can proceed as quickly as possible without waiting at timed stops for the schedule to “catch up” in the event of an early arrival.
- The agency can proactively manage the inevitable bus or train bunching by holding vehicles at stops, allowing vehicles to skip stops, or short-turning (terminating service before the end of the line) some vehicles.
The trouble with headway-based scheduling is that it can make it difficult to plan your trip. If you know you need to be at your destination or meet your connecting service at a certain time, then you don’t know in advance when you should arrive at your origin stop.
To deduce that, you have to anticipate the worst-case scenario: You’ve just missed a train or bus and need to wait for the next one. Therefore, you must add up your expected travel time and the time between each vehicle. If the headway is very low — for example, every 10 minutes or less — then this extra time is negligible.
But in the evening, MetroRapid’s frequency drops from every 10–15 minutes to every 20–30 minutes. And yet, MetroRapid still uses headway-based scheduling during these periods. Thus, when you show up to a MetroRapid stop on a Sunday evening, you can expect to wait between 0 and 30 minutes for a bus to arrive.
This kind of uncertainty is outrageous. Headway-based scheduling should not be used when MetroRapid arrives so infrequently.
How other cities use headway-based scheduling
If I may break out of the Austin bubble for a moment, I’d like to point out that no other rapid bus system uses headway-based scheduling exclusively, as MetroRapid does.
From the Connections 2025 service review, page 29:
Industry best practice is to offer frequency intervals only when service operates every 10 minutes or better during daytime periods with 15-minute service acceptable in the evenings when on-time running is less challenging.
Other cities use headway-based scheduling only during peak times when headways meet that high standard.
This is kind of system Capital Metro should adopt: reap the benefits of headway-based scheduling during the daytime but use fixed schedules for the early morning and late evening periods.
Looking forward: MetroRapid and the new bus network
Capital Metro’s Connections 2025 service review points out the very same issue I’ve discussed in this article. Also on page 29,
In the evenings and on weekends, [MetroRapid] service may run every 20 or 30 minutes. With service frequency over 15 minutes, many customers will opt for the certainty and specificity of Local timepoints rather than relying on less frequent weekend or off-peak frequency at 20 minutes or above.
My emphasis added. MetroRapid’s lack of schedules is not just a problem for a transit geek like myself; it’s an issue that impacts a lot of everyday bus riders. And it’s about to get worse with the first round of Connections 2025 changes slated for June.
Right now, Austin’s transit network is generally designed to provide one-seat rides to downtown and the University of Texas, but Connections 2025 will transform it into a grid-like network that encourages the use of transfers to reach more destinations. I believe that’s a good thing for our transit system, but only if those transfers are easy to understand and simple to make.
Making MetroRapid predictable would vastly improve the experience of navigating transfers in the new bus network. It’s such a simple fix, and with the June changes looming just over the horizon, now is the time Capital Metro should implement it.
Addendum: How MetroRapid is actually scheduled, and why Google Maps lies to you
If MetroRapid ostensibly has no timetable, then you might wonder how Google Maps and the Capital Metro trip planner give you departure and arrival times for future trips.
According to my discussions with Capital Metro, these trips are loaded in the system like regular bus trips, but drivers are not expected to adhere to the departure times; instead, they proceed as quickly as traffic conditions and dwell times allow. In addition, some drivers slow down to try to keep the headways even, and MetroRapid’s dedicated dispatcher can short-turn late-running trips.
However, they MetroRapid does adhere to the departure times at its terminals (Southpark Meadows, Tech Ridge, Westgate, and the Domain) to maintain some level of regularity in the service. So you can think of a MetroRapid line as one long bus route with a single timepoint at the start.
Capital Metro’s official trip planner sources MetroRapid’s real-time arrival data, so it offers accurate directions for trips that you would take soon. Google Maps and most other navigation services do not source this data, so any transit directions that involve MetroRapid can be off by several minutes.
