"what would the death toll be if they had to share the roads with cars?"
Research suggests very few, if any, more than now. Off road cycle facilities are not the safety panacea which many people think- in fact many can be positively dangerous since they're usually designed by planners with little or no experience of cycling. Cycle track to road junctions are particularly bad.
Stats for the UK- where most cycling is on-road- indicate one cyclist death per 33 million km cycled, so it's pretty safe!
Very good analysis of relative safety of on and off road cycling
http://www.lesberries.co.uk/cycling/infra/research.htmlSome highlights include
Verkehrsunfälle mit Radfahrern
Der Polizeipräsident in Berlin. Berlin Police, Germany, 1987.
Berlin Police study 1981 to 1985.
Cyclists 4 times more likely to have accident on roads with cycle paths. Likelihood of serious or fatal injury similarly increased
Safety effects of bicycle facilities
Wegman, Dijkstra. SWOV, Netherlands, 1992.
Originally presented to Roads and Traffic 2000 conference, Berlin, 1988;
Revised version included in Still more bikes behind the dikes, CROW, 1992.
In built-up areas cycle tracks 25% safer than unsegregated road between junctions, but 32% more dangerous at junctions. Cycle lanes 36% more dangerous between junctions, 19% safer at junctions. Seriousness of accidents greater if tracks or lanes present compared with no facilities. Cycle lanes narrower than 1.8m particularly hazardous.
Outside towns, cycle track safety depends on car and cycle numbers.
New cross-town routes in Den Haag and Tilburg had produced no safety gain and had not encouraged much new cycling.
Other links
General injury stats for the UK
http://www.pedalpushers.org.uk/stats/stats...s_in_Road_AccidentsHealth benefits of cycling
http://www.norwichcycling.fsnet.co.uk/Articles/cyclinghealth.htm
