be considered a form of migration. Studies from Canada shows that over one decade the rate of off-road ATV accidents requiring hospitalization increased by 66%, while the rate for snowmobile accidents decreased 20%. Many of these recreational vehicle owners own both or choose one over the other. Data from the US shows that motorcycles are becoming more popular and that motorcycle fatalities are increasing, while car fatalities are decreasing. Many motorcyclists own or have access to a car. Behavior adaptation Rumble strips may gradually encourage inattentive driving – thereby partially negating any safety benefits in the long term. This is referred to as "behavior adaptation". A 2006 US study suggested that airbags and antilock brakes can lead to unsafe driving. A 2007 Canadian study suggested that unsafe drivers are habitual, and that unsafe driving is increasing. A 2009 Canadian study indicated that, after a steady decline, drinking and driving has been on the increase since 2004. These support the migration and behavioral adaptation rumble strip concerns. A safe driver population has more potential for negative behavior adaptation than an extreme unsafe driver population; whereas, an extreme unsafe driver population has more potential for positive behavior adaptation than a safe driver population. Accident rates and profile Different jurisdictions have different accident and fatality rates, as a function of various factors such as climate, road layout, demographics, educational programs, level of policing, driver attitudes toward night driving, promptness of emergency response, and level of medical intervention. For example, the 2006 Canadian motor vehicle fatality rate per province varied between 8.8 and 26.8 per 100,000 licensed drivers per year, with a national average of 13. The 2008 US rate is 20.05. Installing rumble strips on a highway with a relatively low accident rate and low proportion of accidents due to inattention will be relatively ineffective, even if the highway has paved shoulders. The FHWA states: "Long sections of relatively straight roadways that make few demands on motorists are the most likely candidates for the installation of shoulder rumble strips." The degree of engagement of a highway affects the accident rate. Implied in this statement is that highways that are twisty and hilly with a variable foreground have low rates of accidents due to inattention, and are therefore not likely candidates for the installation of rumble strips. Installing rumble strips along a highway that is highly engaging, with a narrow shoulder, a low accident