Thursday, June 10, 2010

Is the bus on time?

We publish schedules for our bus routes that list what time the bus will be at select stops along the route – these scheduled stops are called “timepoints.” Most timepoints are at park & rides or major connecting points to assist people in planning and in making transfers between buses.

We also post schedules at every Community Transit bus stop. Unless the stop is also a “timepoint” the posted time is only an estimate. Route 113 between Mukilteo and Lynnwood, for instance, has 51 northbound bus stops but only seven scheduled timepoints. All the other posted stop times are estimates. To plan a trip, you look at the timepoint before your stop and figure the bus will be at successive stops sometime soon after.

Nobody likes to wait for a bus very long, and it’s even worse if the bus comes early and you miss it. Experienced bus drivers know what parts of the route they tend to run ahead on (and thus they may drive a bit more slowly), and where they tend to run behind (but know they’ll catch up later). If a bus arrives early at a scheduled timepoint, it will pause at that stop until it is officially time to go. That usually blocks a lane of traffic for a few seconds and makes passengers wonder what’s up.

The bottom line is, getting bus schedules right is important. Community Transit regularly tracks the on-time performance of our system as a whole. In May, 93 percent of trips surveyed departed on time. When you consider the vagaries of rain squalls, traffic jams and even the extra time of having lots of passengers board and deboard, that’s not bad. We also have occasional delays due to mechanical breakdowns, passenger or driver illness and construction reroutes.

Last week Community Transit Service Planners asked for my help checking the on-time performance of Routes 105/106, Routes 115/116 and Routes 201/202. I spent four hours at Ash Way Park & Ride in Lynnwood watching buses come and go while also answering customer questions, handing out the new Bus Plus book and learning about transit scheduling from the agency perspective (I already experience our scheduling as a passenger on a weekly basis). I wrote down exactly when buses arrived and departed so that Service Planning can assess whether their route schedules are accurate. Some of the buses I timed started their routes more than 20 miles away in Arlington. We had staff checking the times all along the way – such extensive surveys happen only a few times each year.

We only change bus schedules twice a year, so the public won’t see results of this test until next February (though internal driver departure times and non-timepoint scheduling could change before then). It takes many months to consider changes, test timings and synchronize the schedules in time for sharing with transit partners, coordinating bus and driver needs and publishing Bus Plus books.

Right now we use a combination of sophisticated software and low-tech manual timing surveys and bus driver reports to develop and refine bus schedules. Sometime next year we hope to launch a real-time information system that will make the art of bus scheduling a bit more of a science. No matter what, whether the bus is on time or not will always depend most upon people – the ones inside the bus driving or riding, and the ones outside the bus setting traffic signals, making public policies or causing traffic.

1 comment:

  1. Sell the SwiftBus vehicles. That will provide enough money to restore local Sunday service.