At times, we are told that a road must be widened to provide for "emergency evacuation" in the event that a large number of people must be evacuated by car due to a hurricane, flood, nuclear war, etc.
But beware. In some cases, such an argument is a smoke screen.
When it comes to issues pertaining to evacuation plans, communities need to be on guard against people who have a hidden agenda; people who want to widen roads to promote sprawl and high-speed car travel, and who use "emergency evacuation" as a scare tactic.
By mentioning evacuation, the road widening lobby can achieve the "moral high ground." Who, after all, could be opposed to evacuating the population if there is an emergency? (often, though, the hidden agenda, is to widen the road to promote sprawl, suburban real estate, and happy cars).
Of course, in most cases, there is no hidden agenda. Instead, well-intentioned people sincerely believe that a road widening is necessary to allow adequate evacuation. But the unintended consequence, as we have come to learn, is that the widened road becomes an unstoppable engine for strip commercial, car-happy sprawl.
Whether there is a hidden agenda to promote sprawl or well-intentioned public safety advocacy, the community will be spending large sums of public dollars to create an unstoppable catalyst for more sprawl.
What can be done to avert this smoke screen? Or this unintended consequence?
Most importantly, the community needs to establish a maximum size for its roads. (For example, establishing a policy that states that the community shall never build a road larger than 4 lanes.) Because big roads are very harmful to the quality of life (and sustainability) of a community, the community should decide that, say, 4-lane roads are the maximum size roads that will ever be built in the community. The maximum is a tool chosen by the community to protect its quality of life. That then becomes the "level of service standard" that the community adopts in its growth management plan.
The 4-lane road becomes a much-needed "line in the sand" for protecting quality of life.
I have read over 1,000 books in my life.
Here are my all-time favorites in the fields of transportation and planning, in alphabetical order of author name. The most important or influential books I have ever read in my profession.
The most important books are The High Cost of Free Parking, Cities and Automobile Dependence, The Death and Life of Great American Cities, and The Great Good Place.
Do yourself a favor and read some (or all) of these.
Arnold, Henry F. (1993). Trees in Urban Design, 2nd Edition.