Great that you want to tackle this problem Wanmil. In Basecamp and the newer devices this is a big problem in routing. If you select bicycle mode, the carpool avoidance flag is by default activated. This means that every single road with access=no (even with bicycle=yes!) is blocked because Garmin now ignores bicycle=yes (in Mapsource and older devices bicycle=yes/no is still supported).
What do you mean with "carpool bit is set/cleared"?
Hi Minko, I am really talking about bits (not tags) in the compiled garmin map that define the access restrictions for each vehicle type. One bit is meant to define if a road has/is a carpool lane or not. I will commit a change to the mergeroads branch where mgkmap:carpool is not postprocessed, so mkgmap:carpool=yes sets the bit and mkgmap:carpool=no or mkgmap:carpool not defined will clear the bit in the garmin map. Then anybody can test if there is any usage of the carpool bit. I couldn't find any change in the routing behaviour. WanMil