Cycling will never become mainstream unless you make bike lanes a solid part of all city infastructure. Most people simply just don't feel comfortable riding on the same road as cars. This is why cycling is so incredibly succesful in countries like Holland and Denmark. With bike lanes on every main street, more people will feel safe with using bikes and it will be more socially accepted because there are designated lanes for cyclists only. Cycling will flourish. Bike lanes, bike lanes. Its all about bike lanes.