breadedfishstrip

The biggest thing for cyclists is seperated or protected bike paths. It's safe and much more comfortable for both drivers who aren't used to sharing the road with cyclists, and for the cyclists themselves.

I live somewhere where biking is pretty common as a method of commuting, but even then there are still roads and local areas where biking is just Not Done because of the badly designed street layout.

Edit: One example of something I do like - we have 'bike highways', which are essentially just bikesized roads, usually parallel to train tracks, which allow you to bike in between cities or towns - think distances up to 15miles or so. I've seen those in the Netherlands too, even near highways. Sometimes they even get their own elevated or underground roundabout for crossing dangerous/high-traffic crossroads.

Lake Nyos has been fresh in the back of my head ever since I started hearing more discussion about carbon sequestration in depleted natural gas / oil pockets.