As they say, the power is in the marginal consumer. There are people who, given more bicycle infrastructure, will be helped over the threshold to riding a bicycle for more trips (I'm one of them; I will commute by bicycle, but the roads around me don't make riding home from a store with a trailer a safe decision).
Also, painting more lines on a road is usually more of a half-hearted municipal response to requests for bicycle infrastructure; the changes that are established to improve ridership are physically separated bicycle lanes, the network effect of more cyclists, and holding drivers responsible when their behaviors kill or maim more vulnerable road users.
There is plenty of evidence from many cities around the world. Copenhagen is a rather famous example, their turnaround from being very car-centric to being very bike-friendly started in the 70s IIRC, and the transit patterns followed as planned.
Aren't there studies that show the health benefits out weigh the dangers? I think the problem is more that it feels more dangerous and is, as a result, is often quite stressful.
That's the sort of comparison you can only make over the entire population. Looking at it from the perspective of an individual, it's a raw deal if my general fitness is improved but then two years later I get hit by a car and walk with a limp for the rest of my life.
I do bike commute and lived in Seattle for 7.5 years without a car.
When it comes to transportation infrastructure, you certainly don't want to plan the future based on apparent present demand. Los Angeles vs Copenhagen is a great comparison of the results of continually building for what people seem to want "now" (in the former case) versus building to create a better future.
LA actually has decent public transportation now, and it's getting better. it's also the perfect city for biking, with lower temperature variances, elevation variances, and precipitation rates than most cities. we just need to convert on-street parking into bike lanes everywhere, and we'd be all set (with protected lanes built out over time).
LA may have been the poster child of poor planning in the 80's, but i'd suggest cities like phoenix, houston and atlanta have surpassed it in that regard.
