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Thirty-five percent of the nation’s four million miles of roads are not paved.
In states like North Dakota, there are more unpaved roads than there are paved.
Denise Brown: “I am driving 75 miles on an unpaved road
for my commute to work every day.
I want to make sure that people are aware of the unsafe conditions on the unpaved roads.”
Denise Brown is the training coordinator for the
North Dakota Local Technical Assistance Program.
She trains county transportation engineers on a host of topics including how to maintain
and help ensure the state’s 60,000 miles of unpaved roads are as safe as possible.
Nationwide, nearly 600 people died on unpaved roads in 2017.
Roadway features are a contributing factor to crashes on unpaved roads.
Poor hills and curves, limited sight distance, and a lack of signs
and delineation are also factors.
Another problem is speeding.
More than 41 percent of fatal crashes on unpaved roads in 2017 were related to speeding.
David Veneziano: “They come up on large agriculture equipment, slow moving, taking
up a lot of the roadway, and it’s very difficult, one, to judge how fast they’re coming up
on that vehicle in a lot of cases and two, when they react to it, either slow down enough
or safely pass it.”
Eighty-four percent of the fatal crashes on unpaved roads in 2017
were single vehicle crashes.
Drivers run off the road and either rollover or strike a fixed object
such as a tree or utility pole.
There are several strategies to improve safety on unpaved roads: remove obstacles from the clear zone;
improve sight distances; install and/or enhance signage;
and maintain the road surface.
David Veneziano: “You’re coming around a curve and there’s vegetation,
heavy tree growth on the inside of that curve,
the driver isn’t necessarily able to see around that corner.”
Install advance warning signs and highly visible chevrons at curves.
Add retroreflective panels to the posts of signs to increase reflectivity.
And make sure signs aren’t missing, damaged, or dirty.
Chris Hayzlett: “This is pretty regular to find missing signs like this.
Over 80 percent of our roads are rock.
In a farm community, we get a lot of signs down from big equipment.”
It’s also important to properly maintain the road’s surface.
Denise Brown: “The main focus right now is getting a good spec with the right clay
content in it so that the roads don’t washboard and the gravel is not loose.
The loose gravel tends to be an issue with keeping cars on the road.”
Gary Steiner: “A four-percent crown is important because of drainage.
Anything more than that, like hard rains, wash the fines and the binders
off the road too quickly.”
Loose gravel may cause drivers to lose control of their vehicles.
To address this issue, South Dakota and North Dakota recently developed a plasticity index,
or PI, which outlines how much clay and other materials should be in the gravel.
The PI is now part of their specs.
They’ve also identified a way to reduce excessive dust, which can obscure a driver’s
view of the road and oncoming traffic.
Greg Vavra: “In South Dakota, we use both magnesium and calcium chloride as a dust suppressant.
Three major keys to that – one is material; one is application, which is set by the distributor;
and three is the preparation of the roadway.
You must loosen two to three inches of that roadway, pre-wet it before adding the chloride.
This will usually give you a very tight, hard surface, very safe for the public,
and should last you a year if done properly.”
A significant portion of unpaved roads are rural.
Road owners should understand the challenges
as well as the low-cost treatments available to improve safety.
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