One block, 24 curb spaces, a garage around the corner at $5.00 an hour. Move the curb price and watch what happens to the cars that cannot find a space. Nothing is scripted — the queue in the street is what the price produces.
Curb price
Free curb parking is cheaper than the garage by $5.00 an hour, so every driver tries the curb first.
Curb occupancy
Shaded band = 80–90% target, roughly one space open per blockface
The mechanism on screen is arithmetic: if the price holds occupancy at 100%, an arriving driver cannot park until someone leaves, and the waiting has to happen in the travel lane. How much cruising that produces in a real city is genuinely contested.
35% · 6.0 min
Average share of traffic cruising and average search time across Shoup's compilation of city studies, 2005–2020 (individual cities ranged from 15% to 68%).
Shoup, Pricing Curb Parking, Table 2
32.1 m
Mean distance cruised across 96,765 GPS-tracked San Francisco trips. A companion study found under 5% of trips involved any excess search travel, with a median search distance below 500 m.
Millard-Ball, Hampshire & Weinberger, The curious lack of cruising for parking in San Francisco
5–11%
Transit ridership increase after San Francisco priced the curb to keep one or two spaces open per block. Buses also ran faster. SFpark began at 7,000 meters in 2011 and reached all 28,000 by 2018.
Krishnamurthy & Ngo (2020), via Shoup, Pricing Curb Parking
How to use the gap. Run the simulator to establish that underpriced curb parking must generate queueing — that part is not a matter of opinion. Then put the San Francisco GPS numbers up to bound the magnitude: the older high estimates mostly measured all parking search, not the excess travel caused by a space being unavailable. Shoup's own operational question survives either way, because it is about the price, not the minutes: what is the lowest price that still leaves a space open?