The
Effects of Sprawl on the Urban Environment
Wayne Hurley
There
has been much discussion in recent years about urban sprawl and the effect that is has had
on urban areas. One of the most noticeable, yet often overlooked, effects that sprawl has
is on the transportation systems of an urban area. Increasing congestion on the roads and
streets in urban areas is something that most people have been dealing with for years. The
lack of transit alternatives is also an issue that has been raised; often times transit is
seen as the panacea for relieving urban traffic congestion. While having transit systems
readily available in urban areas certainly is desirable, the amount of relief that they
provide to congested roadways is negligible at best. In this brief article I will site a
few examples of the impact of sprawl on the transportation systems in the Twin Cities of
Minneapolis and St. Paul, Minnesota. I will also list some of the suggested solutions to
dealing with the transportation problems that have developed as sprawl has taken over the
landscape. While I will be focusing on the Twin Cities, many of the examples I'm going to
talk about could be applied to similar large metropolitan areas that are experiencing
rapid suburban growth.
First, a little background: the Twin Cities Metropolitan Area has an estimated 1998
population of approximately 2.75 million, showing a growth rate of 12.4% over 1990's
population of just under two-and-a-half million. Population growth rates are highest in
the counties that ring the two central counties of the metro area: Hennepin (Minneapolis)
and Ramsey (St. Paul). In fact according to the Minnesota Planning department, the fastest
growing cities in the state "are generally outer-ring suburbs or bedroom communities
for regional centers." The fastest growing cities in Minnesota in terms of percentage
are all located 30 or more miles from the core cities of Minneapolis and St. Paul. I can
tell you from personal experience that these cities were all very rural in nature as
recently as five years ago.
So what does this mean for the transportation system? Basically it means that there are
more people in the metro area, and those people are living farther away from where their
jobs are located. More people = more traffic. More traffic = traffic congestion. Traffic
congestion = people beginning to become frustrated, and telling their legislators to
"Do something!" As mentioned above, one solution that is often looked at is
transit; another is roadway expansion. Both have advocates, and both have opponents;
however, under the Federal transportation act TEA-21, emphasis has been placed on transit
as the more desirable solution for solving urban traffic congestion. Unfortunately,
sprawling development and transit do not mix. There are three main factors to consider in
order to understand why this is true: the distance that commuters travel, the direction
that commuters travel, and the type of growth patterns that are prevalent in the suburban
areas. I'll look at each of these separately.
Distance: As mentioned, the distance commuters are willing to drive is increasing every
day, with new subdivisions being developed farther and farther from the core cities of the
metropolitan area. One of the reasons that many people have chosen to live in these
distant suburbs (among many other considerations) is because they have determined that it
allows for a reasonable commute by automobile to and from work. The problem with the
increased distance between where people live and where they work is that it almost
necessitates travel via automobile. Since transit services (including bus and rail) have
to make several stops between origin and destination, most people perceive that it will
take them less time to simply drive themselves. While this may be true now, as traffic
congestion worsens, the gap will steadily decrease.
Direction: Another consideration is that not all jobs are located in the central cities,
as was prevalent many years ago. This has led to an increase in suburb-to-suburb
commuting, as well as central city-to-suburb commuting. Traditional transit systems are
set up very similarly to many freeway systems, in that they emphasize the commute into the
downtown of the central city from the surrounding areas. This pattern does not lend itself
very well to suburb-to-suburb or central city-to-suburb commuting patterns. While some
transit systems have tried to accommodate these relatively new travel patterns, the
origins and destinations are so varied that the ridership levels needed to maintain these
routes are usually not there.
Growth Patterns: The growth patterns that are occurring in the suburban areas basically
consist of sprawling developments, with no interconnectivity between them, often times
except for the freeway and major collector systems. This is probably the biggest detriment
to implementing transit services in suburban areas. In order for a transit system to
sustain itself, dense development is a necessity. Only areas with sufficient density will
be able to generate ridership levels that allow a transit route to continue operating.
Routes that have low ridership are usually dropped, as funding sources are re-directed to
routes that have higher ridership.
Other Considerations: Of course there are several other reasons why transit and sprawling
suburban development don't mix. One of the other more significant factors in the
under-utilization of transit by suburban dwellers is privacy. People like to drive to work
in their own car, and many people have a "phobia" about transit and the people
that use transit.
Solutions? In the Twin Cities
there have been a variety of transit solutions proposed, including light rail (LRT),
commuter rail, and dedicated busways. While it is a good thing that planners in the
metropolitan area are looking at transit options, I don't believe that any of the
proposals will solve the growing congestion problems that face the Twin Cities unless
development and land use patterns are changed as well. While the transit proposals don't
address any of the issues that are mentioned above, it is a step in the right direction
– away from the old mindset that the only way to alleviate traffic congestion is to
build more and wider roadways.
Wayne Hurley is a transit planner in
Minnesota.
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