In this city (Atlanta), we have a big portion of the populous who live out in the country-fried areas and have no problem driving 20, 40, 60 miles to work daily. Those people will never ever set their bums on a saddle.
The only thing that's ever worked for me was referring my roommate to a job position at my company (he doesn't have a car - he used public trans.) and then informing him that there was a lot of cycling involved in getting to work (even though I do own a car). It takes 85 minutes on the bus/train and it takes only 25 minutes on bicycle. Now, he commutes.