SPUR has made the case that an expanded bike network gives residents a safer option to add exercise and subtract carbon from their transportation diet. Better bike infrastructure would benefit tourism as well — although visitors are already discovering the pleasures of biking San Francisco: in 1998, bike rental businesses in San Francisco had combined earnings of $500,000. Thirteen years later, that figure has ballooned to $10 million, according to a post on Streetsblog. These numbers, provided by Darryll White, CEO of Bike and Roll San Francisco, show tourists voting with their feet: even without a fully developed bicycle infrastructure, visitors want to explore the city without a windshield in the way. Bicycle tourism is a growth opportunity, and just one more reason why "bikeability" is a critical component of San Francisco's future — and a critical component of SPUR's recommendations for Fisherman's Wharf (pdf), and the Embarcadero (pdf).