Older parts of the city are good, mostly because the roads pre-date the wide use of automobiles. There are lots of wide avenues and boulevards that make for idea cycling. Most of the neighborhood streets are laid out in a grid pattern. This makes for plenty of alternate routings. Detroit used to be a city of over 1.8 millon folks. It is now about the same size as San Antonio, Texas (about 950,000). There is a lot of empty space here, and traffic can be very light once you get off the "beaten path".

Near-ring suburbs are the worst. They have no facilities for bikes and a generally bike-hostile attitude. The only exception is the mayor of Ferndale a big alternative transport and cycling booster. He is widely viewed as a crack-pot however.

Outer-ring suburbs are less dense, and are generally more bike-friendly, though they have almost no facilities for bikes as transportation. Some of the trails and recreational paths are quite good though. I attribute the less hostile attitude to comparative wealth of the outer-ring suburbs that allows a bigger fraction of the population to use bikes for sport or recreation.

Dan