There have been quite a few improvements in car technology since it was released, but the first Google result I could find says that 1 mph increase in average

There have been quite a few improvements in car technology since it was released, but the first Google result I could find says that 1 mph increase in average speed results in a 5% increase in injury accidents: http://www.trl.co.uk/online_store/reports_publications/trl_reports/cat_traffic_and_transport_planning/report_the_effects_of_drivers_speed_on_the_frequency_of_road_accidents.htm http://www.trl.co.uk/online_store/reports_publications/trl_r...