It has been nearly two years since San Francisco first launched the SFpark program to study how a parking crunch could be alleviated without increasing the supply of parking spaces. In that time, SFpark has attracted the attention of transportation professionals and geeks in the Bay Area and beyond, who are following along with interest as Donald Shoup’s theories are put to the test in a major city with a notorious parking availability problem. SFpark has also been recognized for its innovative streak, which one does not typically associate with the San Francisco Municipal Transportation Agency. The SFpark program has pursued a data-driven approach by collecting granular data and changing meter rates in response to that data on a block-by-block basis — all in pursuit of the price that the market will bear to maintain at least one on-street parking space per block in a handful of pilot neighborhoods.

Parking meter rates were first adjusted in July 2011 in response to data collected by the program, and subsequent adjustments have been incremental in nature. Rates have risen no more than 25 cents at a time and fallen no more than 50 cents at a time, with several weeks elapsing between each adjustment. Absent a special event that significantly increases demand for parking spots, one would expect under normal, static conditions that the need for rate adjustments would diminish over time, with meter rates stabilizing at the market price that manages the demand for parking at a particular time and place.

This behavior can be observed in the rate adjustments that have occurred so far. Yesterday, the SFMTA announced its 10th adjustment to meter rates, which will go into effect next month. For 58 percent of metered hours, no adjustment is needed, and those rates will stay the same as the previous cycle. Rates will increase for 20 percent of metered hours and decrease for 22 percent. At this point, most meter rates are not changing, but that was not always the case. At the start of the SFpark program, about 60 percent of meters were in flux — more were changing than not. Since last spring, however, as more meters reached the right price, the percentage of metered hours with no rate change has grown steadily, and the original situation has flipped.

The effect is even more pronounced looking at adjustments to hourly rates at parking garages. Initially, to make off-street parking more attractive to drivers than hunting for a spot on the street, hourly rates were cut while many on-street meter rates were increasing. Garage rates have since mostly stabilized, within fewer adjustment cycles than for meters. In the two most recent adjustments, 96 percent of hourly rates at garages stayed the same while 4 percent increased.

The SFMTA’s maps for the 10th meter adjustment period (PDF) identify specific blocks and times of day for which meter rates are still too high or too low to achieve the desired level of parking availability. There is some of both in all pilot areas. Neighborhoods where higher rates are warranted include Japantown and the Marina on Saturday afternoons and portions of Hayes Valley on all afternoons. Neighborhoods where lower rates are warranted include Fillmore in the morning and Civic Center. At the Wharf, the data suggests that rates should be lower during the week but higher on Saturday afternoons.