Highways

Toll Roads and Border Politics

I-15 between Nevada and Utah

Last week the Arizona DOT filed an application with FHWA to impose a toll on the 29.4 mile stretch of Interstate 15 within Arizona's border, which links Nevada and Utah. Utah Governor Herbert strongly opposes such a move.

"I strongly oppose any plans to levy tolls on Arizona's portion of I-15, or on any portion of I-15," said Governor Herbert.  "Every state pays into the Highway Trust Fund, and every state receives money from the Highway Trust Fund to maintain the segments of the Interstate Highway System inside their respective borders.  Arizona cannot pick and choose which parts of our national interstate network it wants to maintain.  If Arizona has been negligent in its maintenance of I-15, it should not try and foist its responsibility onto highway users or neighboring states who already pay into the system with their own tax dollars."

Jarrett Walker of Human Transit compares this plan to Virginia's plan put a toll on I-95, one of the state's main corridors, and Arizona's proposal to tax a highway on a remote corner of the state. David King discusses the politics involved of tolling roads at borders, linking to David Levinson, director of the NEXUS research group and Transportationist, and his paper "Taxing Foreigners Living Abroad". (The title is inspired by this Monty Python sketch.)

Any sort of tolling or congestion pricing is inherently fraught with politics. A recent volume of the Transportation Research Record focuses on these issues -  v.2221 Revenue, Finance, and Economics. Equity is also an important factor, and TRB recently published the report Equity of Evolving Transportation Finance Mechanisms, which looks at the equity of evolving transportation finance mechanisms, such as tolling. 

Fewer Accidents due to BlackBerry Outage

Abu Dhabi's English language news publication, The National, reports that the three-day BlackBerry service disruption has coincided with a 20% decline in traffic accidents in Dubai and a 40% decline in Abu Dhabi. 

     "'Absolutely nothing has happened in the past week in terms of killings on the road and we're really glad about that,' Brig Gen Al Harethi said. 'People are slowly starting to realise the dangers of using their phone while driving. The roads became much safer when BlackBerry stopped working.'"

 

 

Friday Seminar - Venky Shankar on Performance Oriented Modeling

This Friday's TRANSOC seminar features Dr. Venky Shankar, Associate Professor, Pennsylvania State University and Visiting Scholar, UC Berkeley, on "Towards a Statistical Basis for Performance Oriented Modeling of Highways - a Safety Perspective."

 

This talk will discuss a strategic approach to the development of a consistent modeling basis for the statistical analysis of highway safety. Barriers to the development of consistent bases will be discussed with respect to the statistical, computational and data considerations. This work is being performed as part of Dr. Shankar's sabbatical visit to UC Berkeley.

 

The Seminar is Friday, October 21, 4:00-5:00, 406 Davis Hall.

Unintended Consequences: Booting Hybrids from HOV Lanes Slows Traffic

 Hybrid car in the carpool lane, Institute of Transportation Studies, University of California, Berkeley

This past July, the California Clean Air Stickers for HOV Lanes program ended for hybrids. What was the effect of this change? How did it affect traffic flow and congestion? That question was investigated by ITS researchers Prof. Michael Cassidy and Kitae Jang, of the Volvo Center.  Their new ITS report, Dual Influences on Vehicle Speeds in Special-Use Lanes and Policy Implications, analysed traffic data and used models to calculate the impact of the added low-emissions vehicles on the other lanes. Cassidy told the Berkeley Newscenter:

“Our results show that everybody is worse off with the program’s ending,” said Cassidy. “Drivers of low-emission vehicles are worse off, drivers in the regular lanes are worse off, and drivers in the carpool lanes are worse off. Nobody wins.”

...

“As vehicles move out of the carpool lane and into a regular lane, they have to slow down to match the speed of the congested lane,” explained Jang. “Likewise, as cars from a slow-moving regular lane try to slip into a carpool lane, they can take time to pick up speed, which also slows down the carpool lane vehicles.”

The paper was also discussed by the New York Times, USA Today, and the LA Times

Raising Speed Limits: Impact on Safety?

Motorway Three

Today the state of Maine raised its speed limit from 65 to 75 mph. Across the Atlantic, today it was also announced that the British government wants to raise the speed limit to 80 mph. Proponents argue that increasing the speed limit will propmote economic growth through reducing congestion, which was touched upon in the TTI report "Speed Harmonization and Peak-period Shoulder Use to Manage Urban Freeway Congestion." Opponents are concerned about the implications on traffic safety. Purdue's Fred Mannering wrote about the relationship between safet and speed in his 2009 article, "An empirical analysis of driver perceptions of the relationship between speed limits and safety." In the report, "Long-Term Speed Compliance and Safety Impacts of Rational Speed Limits," researchers from University of Virginia and VTRC found that increased speed limits along with coordinated education and enforcement can be safe.

 

2011 Urban Mobility Report out now!

San Francisco - New Montgomery St.

The 2011 Urban Mobility Report has been released with week from the University Transportation Center for Mobility, a part of the Texas Transportation Insitute at Texas A&M. 

The 2011 Urban Mobility Report builds on previous Urban Mobility Reports with an improved methodology and expanded coverage of the nation’s urban congestion problem and solutions. The links below provide information on long-term congestion trends, the most recent congestion comparisons and a description of many congestion improvement strategies. All of the statistics have been recalculated with the new method to provide a consistent picture of the congestion challenge. As with previous methodology improvements, readers, writers and analysts are cautioned against using congestion data from the 2010 Report. All of the measures, plus a few more, have been updated and included in this report.

You can download the full report here. They also include summary tables for quick analysis and you can access congestion data for your city and even download the data for all 101 cities. A wealth of information to use in your research. Good stuff!

Friday Seminar - Marta C. Gonzalez on Characterizing Urban Road Usage Patterns

Traffic I Missed

This week's Friday Seminar is MIT's Marta C. Gonzalez presenting "Charactericing Urban Road Usage Patterns with a New Metric." The seminar will take place from 4-5 PM in 506 Davis Hall on 23 September. 

Mobility data from half million anonymous mobile phone users are used for this presentation to study the road usage patterns in the Bay Area. Using this mobility data based on our modeling framework each trip’s route is predicted. Surprisingly, it is found that on average 60% of the vehicles passing through a road segment come from 1% of its drivers’ home locations, hinting to high predictability of the vehicle sources. To quantify the heterogeneous traffic contributions of the vehicle sources we use the Gini coefficient and find that a road segment’s Gini coefficient is poorly correlated with its betweenness, traffic volume, and volume over capacity, suggesting that Gini coefficient is a new metric on top of the traditional measures, quantifying road usage patterns in the perspective of drivers’ demographic distribution. Finally, based on the road usage patterns, we find an efficient strategy to mitigate traffic congestion through a tiny decrease of car usage rates in a few targeted neighborhoods.

Don't forget about Cookie Hour in the library at 3:30! See you then.

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