Ok some number from the UK: http://www.racfoundation.org/m... In 2014, the majority of injured casualties occurred on built-up roads (72 per cent of total casualties). However, the majority of fatalities occurred on non built-up roads (just over a half). Although motorways carry around 21 per cent of traffic, they only account for 5.4 per cent of fatalities and 4.7 per cent of injured casualties. - See more at: http://www.racfoundation.org/m... So 79% of the roads travelled are non highway, giving 94.6% of fatalities. Yes highways (or motorways) are much safer.