Speeding gives you less time to react to unexpected events on the road, and can easily increase your risk of a crash. For this reason, drivers are encouraged to obey speed limits and further reduce their speed during hazardous conditions such as snow or heavy rain.

Some people also take this advice to erroneously mean that reducing their speed can reduce the risk of their own dangerous driving behaviors. For example, vehicles traveling at least 10 miles per hour under the speed limit are often suspected of having intoxicated drivers.

A recent study by the Queensland University of Technology found that drivers who slow down to use a phone while driving will also fail to improve safety on the road. In fact, this behavior can increase the risk of a crash.

"Drivers frustrated by following slow moving vehicles whose drivers have reduced speed to keep talking on their phones may perform aggressive overtaking maneuvers, increasing the crash risk for other road users," said Oscar Oviedo-Trespalacios of QUT's Centre for Accident Research & Road Safety – Queensland.

The study says there has long been a concern that distracted drivers' variable speeds are one factor that can cause conflicts with other road users and increase the possibility of a crash. The study sought to observe how distracted drivers adapted their speed to varying road situations and traffic complexity.

Thirty-two drivers used a driving simulator that included conditions such as free flowing traffic on straight roads, city driving, and heavy traffic on suburban roads. Drivers used the simulator without using a phone, while having a conversation on a hands-free device, and while having a conversation with a handheld phone.

Researchers measured how the distracted drivers' speeds varied from the posted speed limit in the simulator. These drivers were more likely to travel at a lower speed in complex situations such as driving on a curved road or following another vehicle. Drivers were also more likely to select a slower speed than the baseline during the distracted portion of the research if they self-reported safe attitudes toward driving while using a phone or if they had previously been involved in a crash.

"We found that on average, distracted drivers travel at about five kilometers per hour [3.1 miles per hour] slower when following another vehicle and almost three kilometers per hour [1.9 miles per hour] slower in free-flowing traffic," said Oviedo-Trespalacios. "The negative consequences this has on other road users include increased risk of nose-to-tail crashes as a result of sudden stopping, perception of discourteous or aggressive driver behavior, as well as congestion in the transport system."

The results of QUT's research were recently published in the road safety journal "Accident Analysis and Prevention."