A couple of hours ago, our parking guy David La Bua, author of Finding the Sweet Spot challenged your knowledge about curbing the wheels of your car in this mountainous city. What did you guess?

You must curb your wheels when the grade of the street is at least what percent?

A) 0%

B) 3%

C) 20%

D) 25%

E) 50%
 
The Answer is B)  3%

Says David:
This infraction is being cited more and more frequently these days because the City needs your money, and it is an easy one to give a ticket for. The law states that wheels must be curbed if there is a 3% grade or higher on the street.  Ok, but what does that mean? 3% of what?  A 3% grade means that the street is sloped at 1.72 degrees. An apple would have a difficult time rolling down a street sloped at 1.72 degrees.  It looks pretty much flat.  So, unless you have a protractor in your glovebox, do yourself a favor and save $50 by making it a habit to curb your wheels every time you park.

Curbing your wheels actually is important on the hills of SF because if your transmission should slip, or your parking brake should fail, the pressure of the wheels against the curb will act as a block, and prevent the vehicle from running away down the hill. Parking brakes are simply a piece of thin cable that uses pressure to clamp two small pieces of metal to your brake drum or disc.  They have been known to fail.  After all the hard work and strategy that you’ve exerted to find a parking space, make sure that you don’t lose it to gravitational force.

This is not how you want to get your 15 minutes of fame.

If you have a stick shift, park in first gear or better yet, in reverse and use your parking brake.  If your car is an automatic, using your parking brake is good practice too.  Please note: you can receive a ticket if your wheels are curbed, but not curbed properly.

Follow these instructions to curb your wheels properly whenever parked on a hill:

When facing downhill with a curb: Turn your steering wheel all the way to the right (clockwise) so the front of the curbside front tire will touch the curb when you take your foot off the brake.

When facing uphill with a curb: Turn your steering wheel far to the left (counter-clockwise), so the back of the curb-side front tire will touch the curb.

When facing uphill or downhill with no curb: Turn your steering wheel to the right. (Think about it).

If you feel that you have been wrongly cited, you can check out the exact slope of any street in San Francisco on this interactive map. Go to the “Mapped Streets of San Francisco” here.

Photo via Bill in DC on Flickr.com