LADOT and the MUTCD

Canary in a coal mine? Nah - it's a chick under a truck tire.

There are two articles online today that got me thinking, "How does the way the LADOT operates differ from other cities' DOT or Public Works Department?"

The first article, "LADOT's Faster Traffic/Safer Streets Initiative" by Stephen Box of the Bike Writers' Collective , is on LAist. The second is an article stub by Steve Hymon on his Bottlneck Blog and is entitled "Speed limits to increase on some streets".

Both articles deal with the way the LADOT determines the correct speed limits on surface streets in Los Angeles.

State law requires cities to regularly asses the speed limits of their streets, and provides a guide to doing this assesment in the California Manual on Uniform Traffic Control Devices (or the MUTCD). The assessment is, of course, slanted in favor of increasing speed limits - but this can be overridden by other concerns. For example, proximity to a bike lane, a park, a school, or single family homes - all of these types of land use would obviously make a road designer lean toward slower speeds. As you'll soon seen, the LADOT has the option to take the above concerns into consideration using the MUTCD's guidelines, but opts not to.

The assessment the MUTCD requires is called an "Engineering and Traffic Survey" (or E&TS).

The LADOT has performed this survey on several streets in the Valley recently and found, in every case to be presented to the Los Angeles City Council's Transportation Committee this afternoon, that speed limits on the surveyed streets should be increased - from 35 to 40mph, from 40 to 50mph.

The only types of surveys and measurements the LADOT used to make this determination had to do with the average speed of cars travelling on these roads. Their E&TS' mention rates of "accidents per million vehicles", but in every case dismiss these numbers as being beneath some unstated threshold of acceptability.

I can't fault the LADOT with too much - the E&TS guidelines are handed down to them from the State of California. However, they are ignoring choice portions of the E&TS that call for the surveying engineer to use their professional judgement. Here are the additional requirements that an engineer is asked to consider:

When qualifying an appropriate speed limit, local authorities may also consider all of the following findings:
1. Residential density, if any of the following conditions exist on the particular portion of highway and the property contiguous thereto, other than a business district:
a. Upon one side of the highway, within 0.4 km (0.25 mi), the contiguous property fronting thereon is occupied by 13 or more separate dwelling houses or business structures.
b. Upon both sides of the highway, collectively, within a distance of 0.4 km (0.25 mi) the contiguous property fronting thereon is occupied by 16 or more separate dwelling houses or business structures.
c. The portion of highway is larger than 0.4 km (0.25 mi) but has the ratio of separate dwelling houses or business structures to the length of the highway described in either subparagraph a or b.
2. Pedestrian and bicyclist safety.

-E&TS guidelines from pg. 114 in the MUTCD

The MUTCD hands out a set of guidelines to survey speed limits - but as you can see above, the speeds of cars are not the only thing engineers are asked to consider. So, now that the LADOT's work is before us, we can ask:

• "Why did you decide to increase speed limits to 50mph on Reseda Blvd. adjacent a bike lane? Surely it wasn't cyclist safety."
• "Why did you decide to increase speed limits to 45mph on a road that runs through right through a district of single family homes. Surely it wasn't because of the interst of those homeowners."

It's all good - I used my professional judgment and saved this lil' chikin.

That, of course, is precisely what I will ask this afternoon in the City of L.A.'s Transportation Committee. You can join me, Stephen Box, Eric Knutzen, and the members of the Transportation Committee today, Tuesday, August 5, 2008 at 2 p.m. in Room 1010 of City Hall. See you there?

There is one question that I know I won't get an answer to at today's meeting: "How do other cities employ the E&TS?" I wonder how Burbank, Pasadena, South Pasadena, Culver City, Santa Monica, and Whittier deal with this requirement from the State. How do Northern Californian and Central Californian cities deal with this requirement - like Davis and San Francisco?

Our engineers, in Los Angeles, like to refer to "engineering practice" when they run out of excuses for their car-only focus. I think, more than the whining questions I will present to the Transportation Committee today, finding out how other cities deal with the E&TS will be a good way to establish how the LADOT is performing in its role.