Wednesday, February 12, 2014

Bus Stop Location

Two issues concerning bus stops: 1) Their location; 2) Bus bulbouts

Bus stops on the far side of an intersection are superior to buses on the near side of an intersection. There is a naive belief that a bus already stopped for a red light can load and unload passengers at the same time. For a limited number of childless, young, able bodied passengers, this is true. However, the majority of Americans are neither young nor able bodied, a statement doubly true for many bus riders. They are often old, infirm, disabled, or towing children. Further, during peak periods, the time required to board a number of passengers exceeds the length of the 'red' portion of the traffic signal (<30 seconds). Trying to synchronize the length of a load/unload cycle for a bus with the stop/go cycle is bound for failure.

Any stopped bus blocks right-turning cars, either trying to turn off the road, or trying to turn onto the road. For automobiles, the location of bus-stops is moot. But for buses, far-side stops mean that 50% of the time, a bus will be able to travel through on a green light, rather than having to stop at every light, as if it were red, in order to pick up passengers. Given that signalized intersections represent the majority of delay time for urban travel, this represents a significant savings of time and an increase in travel speed. 

A naive student once lauded the virtues of bus bulbouts as an attribute of an effective transit system. Nothing is further from the truth. Bus bulbouts are the are an attribute of an auto-dominated transportation system. A bus without a dedicated lane travels at about 10 mph (including stops). The more frequently a bus must stop, the slower it travels. Urban traffic travels at about 17 mph. This leads to a demand for 'bus pullouts', where a bus leaves the travel lane. Exiting and re-entering the travel lane takes time, making buses even slower. Solutions include reducing the number of stops and improving bus stops. The latter is worthwhile if there is more than one stop within a 400m distance. (Bus poles are cheap and often too frequently placed).The latter improves bus 'dwell' time at a given stop, typically by improving curb and gutter infrastructure to permit level boarding with minimal gap between curb and bus. (One real advantage of rail over bus is faster boarding, due to more efficient 'docking').