Bye, bye Md. countryside. Photo by bettinche.

The Montgomery Planning Department just recommended widening I-270 between Rockville and Clarksburg to 12 lanes, and adding two new lanes north of Clarksburg. The project would cost $3.8 billion, and would be a disastrous move for the County. The analysis relies on antiquated Level of Service analysis that downplays the side effects of the widening on sprawl, and ignores other alternatives such as pricing existing lanes which would alleviate congestion more cheaply and with much less damage.

Widening 270 would fuel the greatest expansion of auto-dependent sprawl in Montgomery County in over a generation. In 1980, foresighted Montgomery County leaders created the Agricultural Reserve, protecting 90,000 acres of farmland in the county’s rural area. They created a program to transfer development rights from agricultural land to the denser, downcounty areas, to focus growth around existing infrastructure and existing jobs.

The Reserve excludes several large areas around Clarksburg and Germantown, and as the Planning Board notes, the County has added significant amounts of new housing there, as well as in Frederick County. However, the report ignores the huge, real effect of induced demand. New lanes would spur even more auto-dependent single-family homes out in these areas, homes very, very far from jobs. The development would put pressure on future County leaders to narrow the Reserve. And, most of all, it would drive even more sprawling growth in Frederick County.

Instead of seeing freeway expansion as driving demand, the Planning Department report simply takes development as static and focuses almost entirely on vehicular Level of Service (LOS). That’s entirely the wrong measure.

Planning Staff have taken a small bite out of LOS-centrism in the proposed Growth Policy, recommending a change in the standard from D to E. But if you’re only designing a transportation network with the goal of moving as many cars as possible as fast as possible, you end up with distorted answers. As the saying goes in transportation planning, “If you plan for cars and traffic, you get cars and traffic. If you plan for people and places, you get people and places.”

The staff report dismisses the “no-build alternative” simply because it will not relieve congestion on the roadway. But it doesn’t challenge the basic assumptions that speeding the drive from Frederick during rush hour should be the County’s priority with $3.8 billion.

Worst of all, the staff never consider better options, like congestion charging on existing lanes. FHWA itself concluded that charging tolls on 270 during peak periods could move enough “discretionary” car trips to other times to alleviate the congestion problems on 270. Freeways behave somewhat paradoxically, where very small changes in demand cause big changes in congestion. Brookings just released a paper recommending a road-use pricing system.

Next: Another way to improve transportation in the corridor, for less than $3.8 billion.