Mobile devise use by drivers before and after implementation of a new Nova Scotia districted driving law

Author(s): Jenny Cartwright, Mark Asbridge

Slidedeck Presentation Only (no paper submitted):

1B - Asbridge


Laws aiming to reduce mobile device usage by drivers have been implemented in a number of jurisdictions both nationally and internationally, but impacts on usage have been mixed. Currently, the law in Nova Scotia imposes fines for using a hand-held cell phone to make calls or send/read text messages, ranging from $176.45 for a first offence to $348.95 for a third or subsequent offence. From February 1st 2015, a new law will increase fines to $233.95 for a first offence and $578.95 for a third or subsequent offence, with the addition of 4 demerit points on a driver’s license if they are convicted. For drivers who carry a learner’s license, these demerit points will result in suspension of their license for six months.

Policy implementation is strengthened by evaluation. Working in conjunction with the Nova Scotia Departments of Transportation & Infrastructure Renewal and Justice, and the Nova Scotia Road Safety Advisory Committee, we will assess whether the implementation of the new law to combat distracted driving is a) necessary and b) effective, employing external data that captures observed rates of mobile device use among the general driving population. We hypothesize that rates of mobile device use by drivers will be lower after implementation of the new law, with lowest rates observed at three-month follow up, and similar, though not as low, rates at one-year follow up.

A roadside observational study of a random selection of intersections in Halifax Regional Municipality, stratified by traffic density, will be conducted to determine approximate rates of cell phone usage before and after implementation of the new law. Trained observers will record data on road traffic volume, number of drivers using mobile devices to text or make calls, and selected characteristics of those drivers (such as approximate age, sex, and type of vehicle). Observations will be made at a number of high- and low-volume traffic intersections, at varying time points (morning rush hour, mid-day, evening rush hour) before implementation of the new law; these observations will be repeated at the same intersections and at the same times of day three months after implementation and one year after implementation.

Rates of mobile device use will be compared pre- and post-implementation to assess whether the new policy has significantly reduced in the Halifax Regional Municipality. Additional analyses will describe differences in rates of driver mobile device use by driver sex, age, vehicle type, time of day, and type/location of intersection. Primary data from this project will be combined with aggregated administrative data from other sources including the Nova Scotia Departments of Transportation & Infrastructure Renewal and Justice, and Service Nova Scotia. These will include charge/conviction rates for driver distraction and mobile device use, and crash/injury rates.

Discussion and conclusions

Although administrative data can illustrate the number of charges, convictions and citations issued for drivers using a mobile device, conclusions drawn solely from this data are limited as police charges are biased by the amount of enforcement directed at the offense. Intensity of enforcement is not indicative of normal police practice, typical charge rates, or normal driver behaviour, particularly after a new law has been introduced. Little attempt has been made to document the observed prevalence of cell phone usage in the general driving population. Using combined data, this study will provide a comprehensive picture of the potential effectiveness of the new law on reducing driver mobile device usage and, in turn, enhancing road safety. In addition, this work contributes to the broader body of knowledge around the impact of distracted driving laws.