Intelligent Highway Systems for Rural Roads-Part of the Series on 'Lessons from the 2nd International Symposium in Freeway and Tollway Operations' Conference in Hawaii

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The 2nd International symposium in Freeway and Tollway Operations was held in Honolulu, Hawaii from June 21-24, 2009. More than 200 experts specializing in freeway and tollway operations gathered from around the world to share their research knowledge and experiences. These series of articles summarize some of the major presentations with useful lessons for Hawaii. This is article 6 of 10.

Scott Nodes, engineer at the Arizona Department of Transportation represented ENTERPRISE, a pooled-fund study consisting of transportation agencies from North America and Europe. Along with Arizona, the pool fund study members include Departments of Transportation from Colorado, Iowa, Kansas, Michigan, Minnesota, Virginia, and Washington State as well as the Federal Highway Administration, the Dutch Ministry of Transport, and the Ministry of Transportation of Ontario. According to Nodes, ENTERPRISE’s current projects are based on rural needs for Intelligent Transportation Systems (ITS). This includes rural renewable power, rural transit and ITS warrants.


These warrants are lists of requirements that would support the ITS decision making process by justifying the need for ITS devices. The warrants would also help an agency avoid deploying unnecessary devices protecting the bottom line as rural areas are requesting more ITS devices than there are funds for, especially when a majority of funds are dedicated to intelligent transport systems in metropolitan areas.

An initial set of ITS warrants have been completed. Four ITS devices were chosen for the initial phase: dynamic message signs, closed-circuit television, highway advisory radio, and road weather information stations. A set of warrants for these assesses the validity of its selection.

For example, an agency identifies dynamic message signs to be a solution to warn of high risk of hydroplaning on a particular stretch of road, the next question to be answered would be “is a dynamic message sign warranted?” Factors to be considered are the number of weather events near the site, the number of crashes related to weather, and the availability of weather information. The agency can then go to the ENTERPRISE website, input all the information and obtain whether the device is warranted or not.

North Dakota used the warrants to decide if dynamic message signs and highway advisory radio were necessary around an Indian reservation. The warrant analysis concluded that the devices were not warranted and recommended low-tech applications like static warning signs and beacons, ultimately saving the state money.

Phase two of this ITS warrant project will develop warrants for five other ITS devices.
These would include radar speed detectors, variable speed limit signs, and ramp metering.
In Hawaii, there are requests from neighbor islands for ITS applications to improve safety on our rural highways. Neighbor islands have implemented the use of radar speed detectors that display to drivers how fast they are traveling. Dynamic message signs could be useful on Maui, in Kahului and Paia, providing advance warning of road closures on the Hana Highway. Such signs would relay actual expectation of delay instead of static messages such as “ROAD CLOSURE ALONG HANA HWY.” Because the state of Hawaii has several hundreds of miles of rural roads, ITS devices should be considered in large rural communities where intelligent system devices are most beneficial. Warrants are a good tool for selection of location and ITS devices during the planning process.

The ENTERPRISE website has performed over 160 warrant tests. Of these tests only 49 devices were deemed warranted, 83 were not, and 28 were partially warranted. With over half of these devices categorized as unwarranted, state DOTs are realizing the benefits of the use of these warrants in the decision making process, thus ultimately saving taxpayer money.

Several states participating in the ENTERPRISE Pooled Fund are small in population, similar to Hawaii. Hawaii should pay close attention to the findings of ENTERPRISE as they are more applicable to Hawaii’s rural highways than research done in larger states like California, Texas or New York. Hawaii may also want to consider joining the pool funded study to share in the technological and institutional experience with other states, and to take a collaborative approach to implementing ITS locally.

‘Natasha Soriano is candidate for the Master’s degree in Civil Engineering at the University of Hawaii at Manoa.’