On-Time Performance

san francisco: winning speed and reliability battles

38 GEARY V A HospMajor San Francisco transit lines take longer than they did a century ago, as they have been obstructed by traffic and slowed by heavy passenger loads using (until recently) inefficient pay-as-you-board methods. A New York Times piece by Zusha Elinson lays out the statistics.  

(It's important to clarify, right away, that this has nothing to do with streetcars as a technology.  You could easily be misled by this subtle bit of anti-bus bias:

In 1920, the F-Stockton streetcar carried passengers from the Financial District at Market and Stockton Streets all the way to the Marina at Chestnut and Scott Streets in a zippy 17 minutes. Today a very similar trip on the 30-Stockton, the successor to the F-Stockton, takes a half-hour if the stars are properly aligned.

In general, streetcars replaced by buses have slowed down more, over the last century, than those that remained streetcars, but that's an expression of how much more was invested in streetcars than in buses.  The main lines that use the Market Street Subway — J through N — have picked up or shed just a couple of minutes from their 1920 times, even though back then they ran on the surface along Market St (about 3 miles) while now they're in a subway, effectively functioning as rapid transit.  No such improvements were made for streetcars that became bus lines, so of course their performance deteriorated more.  In fact, the 30-Stockton relies heavily on maneuverability in unpredictable Chinatown traffic; a streetcar in exactly the same traffic, unable to move around obstacles, would be even slower and less reliable.)

The real message of this story, though, is the need to have a conscious intention about the speed and reliability of transit.  Highway planners ruled the late 20th century with their clearly defined notion of "Level of Service" or cars, which mowed down opposition through its simplistic A-F letter-grades.  Just after 2000, the Transit Capacity and Quality of Service Manual sought, at first, to claim this same authority-through-simplification for transit.  But while the TCQOS is a spectacular reference guide, few in the business believe that a single A-F score can capture the many important ways that transit succeeds and fails.

My own work in this area has always advocated a stronger, more transit-specific approach that begins not with the single delayed line, but rather with the functioning of an entire network.  Don't just ask "how fast should this line be?" which tends to degenerate into "What can we do to make those forlorn buses move a little faster without upsetting anyone?"  Instead, ask "What travel time outcomes do we need across this network?"  Or turn it around: How much of the city needs to be within 30 minutes of most people?  – a question that leads to those compelling Walkscore travel time maps, which are literally maps of individual freedom.

A network speed standard would identify necessary speed standards for each service type, but especially for the Frequent Network, because high frequency means greater impact of delay — both on passenger freedom and the agency's bottom line.  We* used this approach in a Seattle Transit Plan study about 7 years ago:

1.  Define the Frequent Network (every 15 min or better, all day, every day), including any segments that are "Rapid" (faster with fewer stops)

2.  Define the policy operating speed standard for each product (frequent local vs rapid)

3.  Map the existing scheduled speeds on each segment against this standard, creating a map with screaming red segments meaning "deficient."

4.  Prioritize interventions to improve transit speed based on those deficiencies.  

This is quite different from a classic cost-benefit approach in which we count the riders currently on a segment and assign value based on their total travel time saved, because it acknowledges that (a) a dysfunctional segment is probably driving away customers regardless of how many are on it now and (b) the outcome is the network, not just a single line.

We had a lot of success with this in Seattle at the time.  Once the deficiency map was drawn, engineers noticed segments that they hadn't identified as problems before, and went to work on fixing them.  Note too that the method cleanly separates problem from solution.  Don't start with what you think is possible.  Start with what you need.  Define the absence of what you need as a citywide problem that affects the whole network.  Then fix those deficiencies.  If you're going to go to war with three businesses over "their" strip of on-street parking, you're more likely to break through the "big agency attacks struggling small business" frame if you're defending the entire city's transit system.  

Remember: a line is only as reliable as its least reliable point, and a journey through a network is only as reliable as the least reliable of its lines involved.  So one localized problem affecting speed and reliability (such as stops too close together) actually affects a vast area, and drags down public expectations for an entire network product.  If it costs the agency money (as slower service always does) then it's also a direct detriment to the overall abundance of transit service.  That's the frame in which you win battles over three on-street parking spaces, a signal phase, or even an entire tranist lane.

San Francisco's Transit Effectiveness Project is, to a great extent, the culimination of exactly this thought process.  I remember in the 1980s or early 90s a time when Muni proposed to eliminate just one consequential bus stop;  17th & Mission.  The story became: "Big, bad transit agency launches personal attack on the people and businesses at 17th & Mission."  The TEP has worked to change that conversation, emphasizing that on high-frequency services, the speed of every segment is part of the whole city's transit outcomes.  The same process has made it easier to do a range of other locally-hated citywide goods such as removing parallel routes that were too close together.  

Does your city's transit system have a similar project underway, one that moves beyond route-by-route analysis and looks at how every speed/reliabilit deficiency harms the whole city's transit system?


*I was with Nelson\Nygaard at the time.  The project was the City of Seattle "Urban Village Transit Network" study of 2004, which became a foundation of the Seattle Transit Plan.

san francisco: cameras will enforce transit lanes

Lanes that protect transit's speed and reliability are only as good as their enforcement.  San Francisco, like many cities, has long had a few lanes whose enforcement was so spotty as to render them advisory.  Now, the city is getting serious, with camera enforcement and significant fines. 

I think another feature will eventually be necessary:  Full painting of bus lanes in the same way that we usually paint bike lanes, along with signage on approaching intersecting streets, so that there is no "I didn't DSCF5960know" excuse.  Sydney, for example, paints its bus lanes deep red, with gaps at the points where cars can cross for turns.

In addition, if you approach as a motorist on an intersecting street, you will see a sign with a lane diagramDSCF5971 of the street you're approaching, so that there's no excluse for turning into a bus lane.  Fines (stiff) are often advertised prominently.


Beyond “On-Time Performance”

A San Francisco reporter emailed me yesterday with this question, regarding the city’s main transit system, Muni:

As you know, Muni set a goal in 1999 when the [San Francisco Municipal Transportation Agency] board was formed, to have a 85 percent on-time performance standard. That was voted on in 1999 (Prop. E). Since then … the agency has yet to the meet goal or even gotten close to it. The highest it’s been was 75 percent a few months ago.  … I wanted to ask if you if there is any danger for Muni to be so focused on this one standard? Are performance metrics evolving and why are they evolving? What else should Muni to be looking at as far as improving reliability?

Continue Reading →

The Perils of Succeeding “On Average”

Two recent comments on different topics got me thinking about averages, and why people like to talk about them more than they like hearing about them.

Toronto transit expert Steve Munro made this comment on the familiar perils of transit operations in that city:

In Toronto, the TTC reports that routes have average loads on vehicles, and that these fit within standards, without disclosing the range of values, or even attempting any estimate of the latent demand the route is not handling because of undependable service.  Service actually has been cut on routes where the “averages” look just fine, but the quality of service on the street is terrible.  Some of the planning staff understand that extra capacity can be provided by running properly spaced and managed service, but a cultural divide between planning and operations gets in the way.

Continue Reading →

If On-Time Performance is 96%, Why Am I Always Late?

A New York Times article today highlights the perennial misunderstanding embedded in how transit agencies typically measure on-time performance.

By official accounts, 2009 was a banner year for the commuter railroads that serve New York City. Of all the trains that ran last year, the railroads said, nearly 96 percent were on time — one of the best performances since they began keeping records.

But the reality, as nearly any rider would tell you, can be considerably different, and vastly more frustrating. Continue Reading →

Now, Anyone Can Monitor Reliability

Can you think of a better way to measure service reliability than the ones your transit agencies use?  Can you develop ways to analyze the system’s performance that will reveal more precisely where and why things go wrong?  Now, any transit geek with a head for statistics can try out these ideas, and share what they discover, for any transit agency that publishes a real-time information feed. Continue Reading →

Transit Advertising and Transit Self-Esteem




This Air New Zealand ad, on a bus shelter in Sydney, raises the issue of transit self-esteem.   “$100 says the bus won’t be late,” it says, then, in much smaller print: “Looks like you win.”

Should transit agencies accept advertising that demeans their service?

Advertisers are often tempted to do exactly that, especially when selling vacations or other forms of escape from the everyday.  The bus is both a profitable site of advertising and an irresistible metaphor for the tedious life.  If you imagine your transport mode as a romantic partner, the bus in mixed traffic is the worst of both worlds: neither sexy nor capable of commitment.  When advertising on a bus, it’s not surprising that advertisers find ways to play on that. Continue Reading →

If Your Bus is Late, Should the Agency Pay?

An engineering professor in Montréal got his transit agency to pay for his taxi fare because his bus didn’t show up.  Unfortunately, it took many days of his time in small-claims litigation, so his trophy, a $40 check from the agency, should probably be framed rather than cashed.

Now and then a transit agency tries some kind of “on time or we pay” guarantee.  In the Montréal suburb of Laval, for example, the buses are equipped with Global Positioning System (GPS) technology.  The deal is that if your bus is more than five minutes late (a fact that the agency can verify via GPS), you can demand a free bus ticket, which is nice but not much of an incentive for the agency.  It seems to me the same GPS-driven approach could be used to implement a policy if “when we’re more than x minutes late, we stop collecting fares.”  That would actually help a late bus get back on time, because fare transactions are so time consuming. Continue Reading →