Two emails came in this morning about the city's ballyhooed pothole repair effort. One, from Bureau of Street Services chief William Robertson, lectures that I shouldn't have been so skeptical of this week's publicity claiming that 80,172 potholes were repaired in seven weekends of work. He begins by saying that on an average day, 24 crews fill fifty potholes each around Los Angeles, or 1,200 every weekday. The mayor's Operation Pothole ramped up even that pace, Robertson writes:
Operation Pothole was scheduled over a 14 week period and took place every other weekend. The Bureau scheduled 50 crews per day working a 10 hour shift, per weekend. The mean, old, nasty Director of the Bureau set an incredulous (there's that word again) goal of 125 pothole repairs per crew (why not, this was a concentrated effort in a much smaller geographic area with extended work hours).
Question #1 - If the crews worked one weekend in each of the 7 Planning Areas, how many total days did they work?
ANSWER - 1 weekend = 2 days X 7 Planning Areas = 14 days.
Question #2 - If each crew achieved the Director's goal of 125 repairs per day, what was the Director's goal for Operation Pothole?
ANSWER - 125 repairs per day X 50 crews X 14 days = 87,500 potholes.
Question #3 - If only 80,172 potholes were repaired, how many repairs did each crew average per day?
ANSWER - 50 crews per day X 14 days = 700 crews. Divide 80,172 by 700 crews = 114 repairs.
BONUS QUESTION - Is 80,172 potholes repaired A) Incredulous B) Impressive or C) a good effort.
The correct answer is C) a good effort.
Well, that's it for today class - see you around the campus!
Best Wishes for a Great New Year!
Professor Pothole aka
William A. Robertson, Director
Bureau of Street Services
Thanks professor. I'm struck by two numbers. Even before the mayor's call to rid Los Angeles of potholes, crews filled more than 250,000 a year — that's a lot of potholes. And crews that average fifty repairs a day can carry out 114 if pushed. Hmm. The second email pointed me to a blog post by UCLA Law professor Stephen Bainbridge, who is suspicious of the city's math in a different way:
By my math, that's only about $5.60 or so per pot hole. Very curious. That figure struck me as astonishingly low, so I spent a few minutes with Google, and found some interesting comparisons:
* San Diego spends about $25 to repair each pothole. (Link go to p. 235.)
* Denver managed to average just about $18 per pothole. (Link go to p. 35)
* Overland Park, Kansas, spent a whopping $50.49 per pothole. (Link)
So let's just say, I'm a little dubious. Unless Los Angeles has suddenly discovered some secret pothole repair process, something is very rotten in Denmark.
More over there.
* Professor Pothole replies: (1:20 pm)
The City of Los Angeles does have secret weapons! The first weapon is our two municipal asphalt plants. Unlike San Diego, who sold their municipal plants a number of years ago, the City of LA invested in upgrading our plants by adding storage silos and increasing the percentage of recycled asphalt pavement contained in our asphalt mixes. The second weapon is our asphalt recycling program. When we mill or reconstruct a street the old asphalt is recycled into new material...both municipal plants are running 20% recycled and our vendor plant runs 50% recycled. Recycling greatly reduces our costs per ton for materials.
At the press conference I was asked "how much does it cost to fix a pothole?" My answer was $5.00 to $20.00 per repair. Naturally, if a crew goes out and fixes one pothole on a street and then drives 3 miles to the next location and fixes another pothole, your cost are going to be around $20.00 per repair. Now, if it's Operation Pothole and you're targeting some of the worst streets in the City and you repair 20-50 potholes at each location, your costs are much lower! I believe they call that economy of scale!