No need to speculate.
But first, let me note that we can define four zones in Metro Detroit: city of Detroit, inner ring suburbs, sprawl suburbs, rural. Each zone has different cycling and a common mistake is extrapolating the conditions in one zone over another.
The best cycling is clearly in the city of Detroit. In fact, it's the best urban cycling I've done. I wouldn't trade it for Austin or Boulder or any of the designated bike friendly communities I've ridden.
Why?
We have well-formed street grids with extremely low traffic volumes. The traffic volumes are so low that visiting traffic engineering consultants have been in disbelief. Who needs a bike lane when you can take an entire travel lane?
Detroit's population is similar to what it was in the 1920s. And while car ownership is likely higher than that time, we have a well-formed Interstate system to carry the bulk of traffic.
Yes, we did pass a non-motorized plan (400 miles of bike lanes primarily through road diets) and we are beginning its implementation. We've also made over $100 million in greenway investments in the city and anticipate making close to another $100 million when all is done.
We're jealous of Minneapolis and Chicago? That would be news to me. I can say I'm jealous that their cities have more financial resources to invest in non-motorized projects. To date we've had to work nearly exclusively through grants and private foundations.
And yes, we have a fixie culture, but few ninjas.
[If you want a taste of riding in Detroit, come visit us on September 19th for the
Tour de Troit. We've got over 1,000 cyclists signed up already.]