– Dan Majewski
Albuquerque, 2014: Our population is decreasing and high wage jobs are few and far between. Our local government has a growing list of projects to construct and a shrinking tax base. In addition, several indicators in our community have changed since the recession. These indicators range from people per household to average income to home ownership rate. All of these changes have not led to changes in how public (and even private) projects are built and prioritized.
One of those indicators is motor vehicle miles traveled per person or per capita VMT, the topic of this article.
Projections vs. Reality
Building It ≠ They Will Come
This next section is very important. I’ll call it “How Cities Decide to Build More Roads” or “The Road Gods“.
Municipal traffic engineering departments base road construction priorities around something called a Traffic Demand Model (TDM). TDMs are computer simulations that calculate projected amounts of motor vehicles + population + other indicators on city roadways. Based on the results of these models, the Road Gods then decide which roads should be built, expanded or kept as is.
In the words of a local government staff person:
The City uses traffic projections to plan their projects. They are not looking at past traffic patterns but the modeled traffic demand in 2035.
This is an imperfect system to begin with because it does not consider scenarios such as “what if we build LESS lanes?” or “what if we just added sidewalks and bike lanes on every road instead?”
However, since the mid-2000s, these models have become extremely outdated and irrelevant. They are leading to decisions which are having a dramatic negative effect on our local transportation infrastructure.
People Are Driving Less
Below is a chart that captures one aspect of the social changes occurring in the United States today: