Just how much does a bike lane cost anyway?

[omegabytes]

Find out how much it really costs to build a protected bike lane and update the weekly tweet.
Update the reference websites doc with any relevant findings.

The existing weekly tweet contains the following info:

Reports this week: 61
Potential fines:   $8,052
(we could build 0.50 miles of parking protected lanes!)

• Potential fines = number of reports * $134 (fine for blocking bike lane)
• number of miles = $16k / potential fines

I got the $16k based on information here but it's not specific to San Francisco.