I had written earlier that we could not build enough highways to solve
congestion. Someone challenged that assertion and asked for some facts.
This is such a tenent of transportation planning that the folks that I asked
were a bit thrown by the question. But they were able to give me a real
live local example.
Average daily traffic counts reflect the number of cars driving on a road.
A rough rule of thumb is that a two lane highway carrying around 40,000 cars
a day will be congested. A four lane highway around 80,000 a day, a six
lane aroune 120,000 a day. These are rough numbers because what starts
happening is that the peak hours begain to spread out. Rush hour instead of
being from 7:00 am to 8:30 am becomes 6:30 am to 9:30 am and continues until
you have the problem that Chicago has that the highways are congested even
at 12:00 midnight. So roads can go over these rule of thumb numbers but
mostly by adding hours of congestion.
In 1986, Highway 12 was carrying 87,500 cars a day (measured right where it
came into downtown before the I-94 exit). At the time, the road was clearly
having congestion problems. This road was rebuilt from being a four lane
signalled road to a six lane interstate highway at a cost of billions of
dollars. In 1998, this same stretch was carrying 148,000 cars per day, also
clearly congested. Simply put, we spent billions of dollars to take a
congested road and replace it with a larger congested road. History and
survey data shows that enough latent demand exists that if we widened it
again, it would be congested again within a decade, possibly sooner.
There are many factors contributing to this:
- More people owning cars
- Women entering into the workplace
- Fewer people able to share a ride (rush hour auto occupancy is down to
1.19 persons per car) (it is so low that MnDOT has stopped surveying this)
because their work places are located so far apart
- People drive further to get to work
- Many more people in the region with little additional construction of new
highways
- A pattern of sprawling development
Given these societal factors, there is no solution to congestion. As long
as we continue to develop the region like we have and we don't change our
driving habits, we will have increasing congestion problems. There are
three basic strategies to addressing it:
- Increasing highway lanes to provide at least temporary relief and
removing bottlenecks to make the existing highway system more efficient
- Moving people into higher occupancy vehicles, whether they are car
pools, van pools, buses, LRT, commuter rail, which preferably run in their
own dedicated corridor like a dedicated busway or commuter rail so they
don't have to be on the crowded highways
- Having a different development pattern to accomdate the 20% population
growth that the region is going to experience in the next 20 years,
preferably one that is more compact and supports these alternative
transportation methods.
We are going to have to pursue all of these strategies if we are going to
keep the region viable.
Carol Becker
Longfellow
_______________________________________________
Minneapolis Issues Forum - Minnesota E-Democracy
Post messages to: [EMAIL PROTECTED]
Subscribe, Unsubscribe, Digest option, and more:
http://e-democracy.org/mpls
