Unlike auto rickshaws, which burn fuel, cycle rickshaws produce no pollution.
VOA: special.2009.05.11
The problem is most acute in the Central Valley, where nearby mountains tend to trap the pollution sent to the skies from heavy auto traffic and other machinery.
"As a public company, stock is our currency, " explains the company's chief, Steven Schneider, who took the top job when Zap, which stands for "zero air pollution, " bought Schneider's auto repossession business in 2002.
Some experts think the global auto market may actually have maxed out, due to concerns about pollution and sprawl, as I wrote for Forbes earlier this year.