Day: 2011-07-09

Do Freeway Traffic Management Strategies Exacerbate Urban Sprawl?The Case of Ramp Metering

| David Levinson

Recently published:

Abstract
The impact of highway capacity expansion on urban land use has been studied extensively. With the shift of transportation investment priorities from major capacity expansion projects to operational improvements, it has become increasingly important to understand the impact of transportation control measures such as traffic management and pricing on location choices. This paper explores the impact of traffic management strategies on land use patterns using the example of ramp metering. A regression-based transportation model is employed to capture changes in accessibility due to ramp metering on a highway network. A land use change indicator model then estimates how employment and residential density distributions shift in response to changing accessibility in several stylized urban areas with various initial land use patterns (e.g., monocentric and polycentric cities). Ramp metering is shown to improve accessibility in a nonuniform fashion. The resulting land use changes depend on the existing land use conditions. In monocentric cities, ramp metering exacerbates urban sprawl by encouraging residents to live further away from their workplaces, which produces avoidable excess travel. In polycentric cities with both nondominant central business districts and secondary employment centers, ramp metering actually encourages residents to relocate to areas near existing employment centers and therefore serves as an antisprawl measure. The weakest impact of ramp metering on land use is observed when an urban area has a perfect job-housing balance. Other interesting findings suggest that by making downtown areas more accessible, ramp metering may help revitalize declining city centers in congested cities and that business location decisions are not significantly affected by ramp metering.

The first version of this paper was written by Lei as a term paper for one of my classes (I think PA8202: Networks and Places). Unfortunately it is behind a paywall (TRR should be set free, just as other National Academies publications have been), though I am sure the author will happily share a copy.

Circle Pines, Minnesota a planned cooperative

| David Levinson

I also did not know until recently about Circle Pines, Minnesota . Not private like North Oaks (which banned Google Street View), but founded as a cooperative. I am sure I can visit here.
Their website says:

Our community has grown a lot since the early founding days of the 1940’s, but the foundation laid by the early visionaries remains vibrant today in neighborhoods all across the community. Their goal of creating a cooperative spirit is still seen today in the only municipal gas utility in the metro area, providing natural gas service to residents while supporting community services rather than investors.
Every community has challenges and while our city is fully built out so facing no new development, we continue working hard to protect and preserve our natural environment, support and sustain our high quality schools, and maintain our streets and other infrastructure. We’re fortunate to have so many talented people involved in our Parks, Planning and Utilities Commissions, and to have citizens with a strong sense of volunteerism and civility.

History of Circle Pines

In 1945, while lying in the shade of the trees at the picnic ground at Golden Lake after swimming V.S. Petersen sat up and announced “I have an idea”.
V.S. Petersen found two men sympathetic to cooperative notions. They were Thomas Ellerbe, head of the engineering and architecture firm that did the Ramsey County Courthouse in St. Paul, and Paul Steenberg. Steenberg was president of Steenberg Construction Company that had built the Coffman Memorial Union at the University of Minnesota.
In May of 1946 the cooperative village of 1,203 acres was announced “to unite the habitation benefits of a functional and contemporary community with the economic advantages of a consumer’s cooperative.” Each home would front a park or a walkway. There would be adult education, nurseries, educational and recreational activities; and the commercial facilities and services would be owned cooperatively, as would the municipal utilities. The minimum housing costs within 3 specified areas were set at $4,000, $6,000, and $8,000. The maximum for a house was set at $20,000. Each buyer had to purchase at least one share in the cooperative, @ $100 per share.
If an owner decided to sell their home, the development association held the first option to buy. The terms were decided by a three-member panel representing the association, the owner and a neutral party. The developers anticipated construction of 500 homes in the first two years, and that it would take five years to complete the total project. The 3 developers planned to turn over control of the development to the homeowners upon completion. For every 500 homes sold, one of the sponsors’ three votes would be transferred to the residents.

City of North Oaks, Minnesota

| David Levinson

I did not know until recently about the: City of North Oaks:

“Located in the Twin Cities, just northeast of St. Paul, Minnesota, North Oaks is a unique suburban community.  With a rich history and emphasis on retaining the natural environment, North Oaks celebrated its 50th anniversary in 2006.
Approximately 4500 residents call North Oaks home.  Because residents’ properties extend to halfway across the road, all residential roads in the City are private and for the use of North Oaks residents and their invited guests only.
The City owns no property.  With residents owning the roads, the North Oaks Home Owners’ Association owns the park and recreation areas and trails throughout the City.
This website is run by the City of North Oaks and serves as a major communications tool for the entire community. Here you can find information about the operation of our local government, homeowner’s associations, community news, promotion of local events and answers to many frequently asked questions. “

I would visit, but I would not be allowed in, unless someone scores me an invite. I wonder if their international roughness index is better or worse than similarly situated suburban subdivisions.

(Via Bruce Benson.)

‘Up to’ 25% of Accidents Are Associated With Gadgets

| David Levinson

Mashable reports: ‘Up to’ 25% of Accidents Are Associated With Gadgets [‘scare quotes’ added by me — dml]:

“A new study from the Governors Highway Safety Association (GHSA) highlights the impact that cellphones and other gadgets can have on car crashes. According to the study, as many as 25% of U.S. car crashes are associated with drivers distracted by a cellphone or gadget.
Produced using a grant from State Farm, the GHSA report, titled Distracted Driving: What Research Shows and What States Can Do [PDF] looks at the main external driver distractions. Not surprisingly, talking on cellphones, fiddling with gadgets and texting while driving are some of the most common driver distractions.
After reading the 50-page document, it’s clear that this study contains as many certainties as uncertainties. As GHSA Executive Director Barbara Harsha says in a statement, “Much of the research is incomplete or contradictory. Clearly, more studies need to be done addressing both the scope of the problem and how to effectively address it.”
Still, one certainty is that cellphone usage increases the risk of crashing and texting is likely more dangerous than using a cellphone.
Understanding that drivers who text or talk on the phone are more likely to get into car crashes than those who don’t, what can be done to decrease these distractions?
Unfortunately, the GHSA study is inconclusive on the effects of both texting bans and public service announcement campaigns for distracted driving.
From the report:

Laws banning hand-held cellphone use reduced use by about half when they were first implemented. Hand-held cellphone use increased subsequently but the laws appear to have had some long-term effect.
A high-visibility cellphone and texting law enforcement campaign reduced cellphone use immediately after the campaign. Longer term effects are not yet known.
There is no evidence that cellphone or texting bans have reduced crashes.
Still, the GHSA encourages states to pass more bans of driving while texting and while talking on cellphones — hands-free or not.

“

The headline number seems far too high to me, but if even close to true, imagine the progress we would have made on fatalities if we were as gadgetless as we were about 15 years ago. (I know, crashes != fatalities). A 25% reduction would amount to about 100,000 fatalities over a decade. Of course cell phones save lives too, due to much faster response rates. All in all, one more reason to take the driver out of the loop and legalize robot cars.