Investigation of behaviour and opinions of 1721 cyclists during 42 hours at 15 locations in Vienna (lanes for mixed traffic including rails, narrower than 4,50 m). Conclusion: It seems possible to lead cyclists along lanes with rails if they are 4,00 m or more wide, if the average speed of cars is below 40 km/h and if there are less than 400 cars/h and 15 trams/h per direction.