As I write this, the famous Bay Bridge connecting Oakland to San Francisco is closed for four days of construction. This vital link between two major cities normally carries tens of thousands of cars (hundreds of thousands, maybe?) every single day between the two sides of the San Francisco Bay. So did the closing lead to massive grid-lock? Are people unable to get around without this major highway--without being able to use their cars to get where they need to go?
On the traffic report today, the worst traffic snarls were in San Jose, nearly an hour south of the bridge in an area absolutely unaffected by the closing. People were told about the closing ahead of time and made other plans. Some went the long way around, adding 10-20 miles to their trips by using other bridges. But most, apparently, resorted to public transit, since the other bridges didn't have much higher volume than usual. And word is public transit is handling the extra capacity just fine. I'm sure there will be some minor snags here and there...hard to reroute 100,000 people without some unexpected incidents arising. But all in all public transit has demonstrated just how flexible and accommodating it can be.
The point is that we don't need to stay on the treadmill of endless road expansion. Building new roads just encourages more driving, and more congestion. Narrowing roads, closing roads, these activities encourage people to find other options. And people are usually smart; they'll find another way. Shifting our nation to a cleaner, more efficient form of transportation isn't nearly as hard as critics make it out to be. Stop spending on roads, build better public transit. People will adapt just fine. The proof is on the (empty) Bay Bridge right now.