Orphan Road

Cascadia Prospectus reports that there's a new study underway to change the way real-time bus info is captured. The current system involves having the bus pas a series of mileposts, which doesn't work too well in crowded areas or when the bus has to divert its route due to construction or snow. The new method would involve GPS and/or Wi-Fi, which "would vastly improve the tracking in the urban area."

Another part of the study would involve counting passengers. Perhaps the algorithm somehow uses the number of boardings to determine how many stops the bus will have to make, and uses that to calculate the arrival time.

This makes it clear just how tricky real-time bus information actually is to implement. With a train, it's relatively straightforward: trains don't get stuck in traffic and make regular, predictable stops. But even the most sophisticated GPS bus system can only tell where the bus is right now and then make a guess about how long it will take to close the distance between the bus's current location and yours.

In most urban areas, though, that's probably enough if you're a regular commuter. If the system can tell me that the bus is still a half-mile away, I can make a reasonable guess about when it will get to my stop. Also, if I have the option of taking the local or waiting for the express, all I need to know is how far behind the express is relative to the local. Exact times don't really matter.

CP also points to this 2003 P-I article on the Mybus pilot program in North Seattle, which goes deeper into the local v. express dilemma.