Lessons from TriMet, Part 1: How do you like your bus system?

This article deals primarily with Portland's transit agency, the Tri-County Metropolitan Transportation District of Oregon (TriMet), using basic transit simplicity.

Everyone understands a line. It is the shortest distance between two points. Roads often travel in lines, and buses run in lines. Except when they don't.

This is a real transit map, located on a bus stop pole. It is supposed to explain to you where a bus travels.

Where does line 1-Vermont travel to, and how does it get you there? Where is "Maplewood," which doesn't appear on the map? When bus lines drive in circles, it's hard to think of an easier way to confuse riders. As an experienced transit rider, I immediately have the following questions:

1. Which loop does this bus travel on first?
2. Is each loop served in the same frequencies and times, or does it vary by time of day?
3. Which direction does the bus travel in the loops? Does this reverse during evening and afternoon rush hours?
4. Is it faster to walk than to take this bus?

This bus route looks like a catch-all route that was designed as lifeline and essential commuter service for a small group of vocal and/or exceptionally needy individuals. This an important part of the trifecta of transit, which is essential enough to merit its own post at a later date. One final question to draw from this map: where does the bus start and end?

This is hardly an isolated example of trying to cram too much information about a complex system in to a small space.

So... when does it run?

Runs every day? Runs once per day? Runs every weekday? This statement is ambiguous as it is pointless. When is the first bus? The last bus? What is the frequency? More questions are asked than answered by such a statement.

Transit aficionados have heard the saying "frequency is freedom". However, there is a point when frequency becomes too frequent and the system simply fails to provide better service by adding an additional bus to serve a line. This is nearing that point:

This line is leapfrogging.

Each bus is held up in traffic, stuck behind the bus in front of it. The buses are unable to proceed more than one stop in front of the other without delaying the one behind it. Essentially, this is a negative feedback loop, and it is very common when agencies "throw more buses" at the problem of high demand. In this case, we are nearing peak rush hour. More service isn't adding anything.

Here is a simple solution: create a higher level of service. Instead of operating the line (in this case, Bus #12) every 3-4 minutes, operate it instead every 6-7 minutes. Then, create a parallel line.  This new line, the 12L or 12E (Limited or Express) can serve less stops and provide a higher level of service.

This is the basic principle of the slow evolution to Bus Rapid Transit (BRT).

Lessons from TriMet, Part 2: Rail will be posted at a later date.