Washington, Apr 12 (ANI): Instead of following speed limit criterions on various roads, people follow their own judgement to gauge how fast they should drive on gravel roads, according to a Kansas-based study.
For the research, Kansas State University scientists Sunanda Dissanayake, associate professor of civil engineering, and Litao Liu, graduate student in civil engineering, studied the actual speeds on Kansas gravel roads and the various factors involved.
"We found that people are driving at speeds based on their perceptions and existing conditions - regardless of the speed limit," said Dissanayake.
By state law, gravel roads in Kansas have a speed limit of 55 mph and are not posted, though local governments are allowed to reduce the speed limit within their jurisdictions.
Dissanayake said the Kansas Department of Transportation wanted to know the better approach in setting speed limits on gravel roads.
Also, the study is important for county engineers who face complaints from county residents who ask for the speed limit to be lowered.
For the project, the researchers collected speed data on Kansas gravel roads and used automatic traffic counters to collect speed of drivers without their knowledge.
They monitored 41 sites, each for about one week and tried to find out if there was a difference between actual driving speeds and the speed limit.
The researchers also looked at various factors like the different types of gravel roads; the number of crashes on the gravel roads; the width of the roads; the amount of heavy vehicles and traffic parameters like volume.
Besides, the researchers sent surveys to residents living near gravel roads.
Dissanayake said the project only looked at straight sections of roadways and avoided curves, slopes, bridges and other factors that likely would affect the drivers' speeds.
It was found that people drove faster when gravel roads were sandier and when they were wider.
The researchers also found that heavy vehicles drove faster than smaller vehicles.
However, when it came to speed limits and the actual speeds driven, the difference was not significant between 35 mph and 55 mph roads.
Dissanayake claimed that the study shows that people drive at a speed at which they are comfortable.
An additional factor, according to her is that people know gravel roads are not highly enforced by police.
From the drivers' surveys, it was found that those who live next to gravel roads know what the speed limit is, and they drive at a speed at which they are comfortable.
The research will be presented at the Kansas Transportation Engineering Conference at K-State. (ANI)