This topic focuses on identifying factors that can cause or contribute to a crash and increase the crash risk.
From Table 6, it can be concluded that the lower values of Q, C M and Q DL are probable to increase the crash risk and the higher values of Q D, V D and W ea will lead to higher crash possibility as well.
For example, a meta-analysis of the safety value of median barriers concluded that cable median barriers increase the crash rate by 30%, but reduce the chance of sustaining a fatal and personal injury when in a crash by 20 and 10%, respectively (Elvik 1995).
A very important study released early this year by the National Highway and Traffic Safety Administration found that consuming marijuana does not increase the crash risk of the driver.
Many such technologies are thought to increase the risk of driver distraction since they may increase the likelihood that the driver will take his or her "eyes off the road" during the driving task and hence not focus on the traffic conditions (i.e., become 'distracted') thereby increasing the crash-risk.
Only three of the reviewed studies included calculations of odds ratios at differing tetrahydrocannabinol concentrations; in all three studies, raised amounts of the substance increased the risk of crash.
Officials say the barriers and roundabouts have in fact increased the potential for crashes, vehicle damage and minor injuries for some users.
Although motorcycle registrations also increased, the rate of crashes per 10,000 registrants remained the same, indicating that there was little change in driving habits, road conditions or the risk behavior of riders.
The lengthy processes of gaining consent to participate in a trial in the emergency care setting, has recently been shown to directly contribute to increased mortality (The CRASH 2 trial [ 17]).
