So, what's a "Controlled Access Road"?

Have you ever heard of the term "Controlled Access Road"? That's transportation engineer speak for a highway that has been specially engineered for high-speed travel.
Known as "Interstate" or "freeway" here in the US, controlled access roads are "motorways" in the UK and New Zealand, as "autoroutes" in France & Quebec, as "autobahns" in Germany and so on. The first such road was in fact the "autostrada" built in Italy in the 1920s.
Whatever the term, all these roads are designed exclusively for high-speed vehicular traffic with an emphasis on engineering that helps regulate traffic flow and vehicular entrances and departures.
These roads are built for speed, literally: many design elements enable high-speed and high-volume travel, including the fact traffic can flow unhindered by traffic signals, intersections or property access. Controlled access roads are also free of at-grade crossings with other roads, railroads, or pedestrian paths, which are instead carried by overpasses and underpasses across the highway.
This type of safety engineering enables smooth transitions off and on the road. Entrances and exits to controlled access roads are provided at interchanges by ramps (called "slip roads" outside of North America), which allow for speed changes between the highway and arterial thoroughfares and collector roads. On the controlled access road, opposing directions of travel are physically separated by a central reservation or median, such as a strip of grass or boulders, or by a traffic barrier.
Counterbalancing the controlled access roads' safety regulations and streamlined design are non-controlled access roads, which present significantly more structural obstacles that can yield greater rates of serious and fatal accidents. On these roads, drivers must contend with obstacles not present on the freeway, including intersections, opposing traffic and unyielding objects like poles and trees that are in close proximity to the road. The lack of regulating "obstacles," like medians, is another key factor increasing risks on non-controlled access roads, specifically. Poor visibility and unregulated or abrupt vehicular entrances combine with these other risk factors to present a serious challenge to fleet owners wanting safe outcomes for their drivers.

This is supported by research conducted by North Carolina State University and the Virginia Tech Transportation Institute, using data from 2005-2009, on fatal crashes involving combination-unit trucks. Analysis showed that 72 percent of fatal crashes in North Carolina, and 59 percent of fatal crashes in Virginia, occurred on non-controlled access roads. The study also points to the need for more trucking consideration when designing local roadways. By considering truck traffic in non-controlled access road design, states will be able to improve safety while accommodating increasing commercial traffic.

As an industry it is important for us to be aware of the different conditions and driving awareness required depending on the type of road we're on. To help, you can ensure drivers are provided training on the different risks associated with road type, and even get involved in conversations about road design and planning with your local government. When was the last time you talked to your local road commissioner about how trucks fit into their road plans?

This entry was posted on February 25th, 2013 by jhubbard and is filed under Recent News & Updates.