At a discussion at our Bay Area Transportation Club, a colleague from Germany remarked how America seems to be obsessed with stop signs. Indeed, we tend to stop at stop signs when we often don’t have to, and stop signs are often used as deterrents against speeding instead of their intention for allowing cross traffic/pedestrians through.

A quick scaling exercise:

San francisco is approximately 7x7 miles. If every mile of road has, conservatively, 5 stop signs, that leads to about 5^2 * 7^2 stop signs in the city. That is approximately 1225 stop signs.

According to SFCTA, “ Ride-hail vehicles drive approximately 570,000 vehicle miles within San Francisco on a typical weekday”, and this accounts for about 20% of the total amount of miles driven. That means, around:

2850000 miles per day total, for all vehicles, on a typical weekday.

741000000 miles per year (excluding weekends)

3705000000 stops per year

According to law, a motorist must stop for at least 3 seconds at a stop sign. This translates to around 11115000000 seconds of wasted time per year. Just in San francisco.

According to this source, idling emits around 0.588g CO2/second. This translates to roughly 6535 tonnes of CO2 per year in San Francisco alone.

Negative Externalities created: The infamous california stop.

Assumptions: