PlanItMetro

Adopted from queueing theory, this new method of assessing delay on transit systems with tap-in-tap-out fare systems accounts for natural variations in customer behavior.

As you may have heard, Metro is testing out a new customer-oriented travel time performance indicator. Many departments here at Metro have been collaborating on this effort. Metro has decided to initially pilot a measure where we define delay as anything greater than train run time, a headway, and the 1-3 minutes it takes to travel from the faregates to the platform. However, as we began our research into customer travel time, we got to asking the question, “How do we define customer delay on the rail system?”

As we quickly learned when digging into the data, on good days with no delay on the rail system, there is still a wide variety of “normal” customer travel times. Some variation in travel time is because customers arrive at random to the origin station, but all leave the destination station more or less at once.  Additional factors influencing this variation include walking speed, use of elevator vs. stairs, escalator or elevator outages, and customers with suitcases and strollers.

We could start with a threshold for “on time” but by definition we know on a good day there were no rail delays so we would be counting slower customers as “late.”

Additionally, on a day when we know a disruption has occurred, we might count very quick customers as “on time” when in fact we know that everyone experienced some delay.

So we set to determine a method for calculating delay that accommodated for the natural variation in customer speeds.  These travel time curves started reminding me of delay calculations from queueing theory from grad school. Read more…

The actual economic benefits of Metro far exceed what planners estimated in 1969, and it’s worth remembering as we consider future transit investments.

In the late 1960s, when Metrorail was nearly about to begin construction, Metro published a forecast of the economic benefits of Metrorail.  The report made rosy projections of the all the travel time and costs the network, then a 97-mile proposed rail system, would bring.  (It also included photos of the pretty awesome 3-D model of a station, including maybe a one-car train?).  Now, four decades later, were the projections right?  Has Metrorail produced the benefits we thought?  The answer is yes, and then some.

Cover of a 1969 report estimating the economic benefits of Metrorail

At the time this report came out, the region was about to make a substantial investment in public transit , probably not unlike today, where we face real choices about whether to invest in Metro 2025 initiatives such as 8-car trains, the Purple Line, or bus lanes.  To quote the report,

Metro is ready for construction. The routes have been selected. The program for local financing has been approved.

How feasible is Metro? Who will benefit?  Will the benefits justify the costs? Is Metro a good public investment for the National Capital Region and its financial partner, the federal government?

The report tallied up all the time savings to riders – former motorists, former bus riders, and truckers – as well as the travel cost savings like avoided parking, vehicle savings, operating cost savings, and more.  It concluded that Metro would save $186 million per year in 1990$, roughly equivalent to $310 million/year in today’s dollars after adjusting for inflation.  Read more…