David R. Henderson  

Some People Won't Like the Results? Let's Quit Measuring Them

Will on Somin on Judicial Revi... The Orange Moon...

Great Moments in Cost/Benefit Analysis

California's S.B. 375 mandates that cities increase the population densities of targeted neighborhoods because everyone knows that people drive less in higher densities and transit-oriented developments relieve congestion. One problem, however, is that transportation models reveal that increased densities actually increase congestion, as measured by "level of service," which measures traffic as a percent of a roadway's capacity and which in turn can be used to estimate the hours of delay people suffer.

The California legislature has come up with a solution: S.B. 743, which exempts cities from having to calculate and disclose levels of service in their environmental impact reports for densification projects. Instead, the law requires planners to come up with alternative measures of the impacts of densification.

This is from an excellent post by Randall O'Toole about a major change in the way the state government plans to measure environmental impacts of transportation. The post is titled "California Thinks Your Time is Worthless."

The state government is saying, in effect, "We know that certain measures we want will increase congestion and we know that congestion eats up people's time, so let's quit measuring congestion." If you think I'm exaggerating, do as I did and read the 13-page draft, "Preliminary Evaluation of Alternative Methods of Transportation Analysis," put out by Ken Alex, director of the Governor's Office of Planning and Research.

In my cost/benefit analysis course, one of the things I teach is that one of our most valuable resources is our time. As Randall O'Toole points out, the California government has decided not to measure time saved or time lost from various initiatives. He writes:

[T]hey [the state government planners] ignore the impact on people's time and lives: if densification reduces per capita vehicle miles traveled by 1 percent, planners will regard it as a victory even if the other 99 percent of travel is slowed by millions of hours per year.

O'Toole concludes:
The real problem is that planners and planning enthusiasts in the legislature don't like the results of their own plans, so they simply want to ignore them. What good is an environmental impact report process if the legislature mandates that any impacts it doesn't like should simply not be evaluated in that process?

All of this is a predictable outcome of attempts to improve peoples' lives through planning. Planners can't deal with complexity, so they oversimplify. Planners can't deal with letting people make their own decisions, so they try to constrict those decisions. Planners can't imagine that anyone wants to live any way but the way planners think they should live, so they ignore the 80 to 90 percent who drive and want to live in single-family homes as they impose their lifestyle ideologies on as many people as possible. The result is the planning disaster known as California.

Comments and Sharing

CATEGORIES: Cost-benefit Analysis

COMMENTS (12 to date)
Pajser writes:

Hiding of harmful information is typically human and notoriously common in politics. It can be reduced with "checks and balances." In some countries almost all documents written in institutions are publicly available. On market, hiding of unpleasant information is rule; it is done routinely and public can do little about that.

Kushana writes:

Unfortunately, the linked documents don't contain enough information to determine whether California is trying to sweep time costs under the rug.

What does seem clear is that the authors are unhappy with LOS as a metric for transportation planning, and would like to use one or more that can incorporate more aspects of the things they are trying to maximize, including time losses.

Health, equity, fiscal and economic effects, and access all incorporate aspects of time. VMT, MVHT, and Fuel Use all directly correlate with congestion.

City management is a complex compromise, full of opportunity cost decisions. I think it's appropriate to search for a metric that can better address that complexity rather than stick with a poor proxy.

Daniel Kuehn writes:

I agree with Kushana - I'm not getting the same message from the document. It seems to emphasize a point I was curious about from the second paragraph of this post: what does time in traffic have to do with environmental impact?

And when you open the link that seems to be exactly their concern: developing metrics that are more likely to get at the environmental impact and less likely to get at something else. It just seems like a bad measure for environmental impact purposes.

If this were a rule for broader CBA's that would be disconcerting. But it's not, right?

TallDave writes:

Wish I were surprised. Government by deliberate ignorance is becoming more the rule every day.

We've replaced evidence-based policymaking with policy-based evidencemaking.

Brad writes:

I just returned from holiday in Singapore, a city whose planners know how to reduce congestion. In the central business district, the government installed Electronic Road Pricing (ERP) to help reduce traffic during peak hours. If you wish to drive there during rush hour, you'll pay more in cash, but your commute will be traffic free.

There are other reasons that Singapore traffic isn’t horrible, but ERP has proven very successful. Perhaps one day American city planners will face the realization that waiting in traffic isn’t “free” and adopt policies to reduce the time Americans spend wasting away in traffic.

Kelly Hall writes:

I really don't envy the OPR's task here: everyone has a metric or two that really matter to them, and in any project there will be hard trade-offs for who to make happy and whose ox to gore. (Want to reduce commute times? Just make all roads 12 lanes wide. Oh, that's too expensive in land and materials? How sad...)

It's very likely that the most valuable metrics vary between different projects, perhaps based on the local population density, current land uses, and other project-specific variables.

Instead of trying to find "the magic metric", I'd prefer the OPR have a standard list of "good enough" metrics that the project stakeholders can understand. Ultimately, the goal is to communicate design trade offs to the stakeholders so that THEY can understand the facts of the project.

Nacim writes:

The real problem with Level of Service is how myopic it is in measuring improvement. It only measures how much a given project inconveniences drivers, and doesn't take into account improvements to walking, biking, or transit.

Here's an article that goes into much more detail on the pitfalls of relying on LoS: http://dc.streetsblog.org/2013/10/03/the-beginning-of-the-end-for-level-of-service/

"Level of Service, simply put, is a measure of vehicle congestion at intersections. Projects are graded from “A” to “F” based on how much delay drivers experience.

That’s all it measures: the free motion of motor vehicles. And that’s the problem. The safety of people on foot and on bikes doesn’t enter into the equation at all, and transit vehicles carrying dozens of people are subjugated to the movement of private cars."

Hazel Meade writes:

The thing about high density population centers is that they only reduce congestion IF you can actually get people living in them to stop driving their cars. If everyone lives in a high high-rise apartment building and STILL owns a car and drives to work anyway, the congestion in and out of that apartment building's garage will be murder.

Thus densification makes congestion worse because humans aren't that easily persuaded to abandon their automobiles.

From personal experience, the only places where high population density leads to less automobile use is where the congestion is so horrific that people would rather walk, or move closer to their work. i.e. Downtown Manhatten. And then, the congestion doesn't get any less bad, it just becomes the domain of the truly stubborn and/or tolerant. I have never seen anywhere with a high population density and low traffic congestion. If such a place existed, people with cars would quickly move there and cause traffic congestion to rise.

Nacim writes:

You can't really have both easy flowing traffic AND a walkable environment. The two are strictly against each other. Local areas trying to improve walkability or catering to other modes of transportation were stymied by the myopic Level of Service metric that only measured how much drivers were inconvenienced and nothing else. There is acknowledgement that congestion and therefore time wasted in cars is likely to increase, but that's counterbalanced by improvement other modes of transportation.

Nacim writes:

If people are still too stubborn to let go of their cars, that's really their problem. Others will be treated to a more welcoming environment when biking or walking because cars are slowed down.

Peter H writes:

Missing from this as well is that we are talking about removing the measure of traffic congestion from the red tape you need to develop your property as the market demands.

I would like David to answer the question framed thusly:

Should the government have the power to prevent land owners from building the type of housing demanded by the market because of road congestion? If so, why? If not, why should such congestion be required to be analyzed as part of a building permit?

Jason Scheppers writes:

First, what a great topic. Randal O'Toole has done more than any one in asking: "What are the trade offs in transportation issues?"

For all the miss direction that is going on by the governmental planning agencies, I think that Dr. O'Toole is right on track that planning agencies do not want to measure truly revealing metrics on how well the transportation system is working.

But as counter point, we proponents of rational cost benifit analsys should be honest regard the bluntness of many congestion measures.

I point to the fact that on a freeway both 20 mph traffic and 10 mph traffic are designated as level of service "F". Improving traffic flow from 10 mph to 20 mph eliminates 3 minutes of delay per mile. While going from level of service D to level of service A (from 46 mph to 65 mph) would save 0.38 minutes of delay per mile.

I hope you can see the drawbacks from using level of service. The question is of course what is better. I suggest David Levinson's, U of Minnesota accessibility measure. It measures how many places you can reach in a certain amount of time. Being complainy, I would prefer a fuller measure of cost be in the denominator, but accessibility is a far superior measure compared to level of service.

It is the nature of a metro regions to grow and have more congestion, and there are balancing forces to how much congestion can be mitigated. Accessibility and a measure of cost on providing accessibility would lead us to much better path forward.

Levinson blog referencing Accessibility Measurement:

Comments for this entry have been closed
Return to top