India's ubiquitous autorickshaws (and the Filipino Tuktuks and their equivalents in Thailand) are among the filthiest soot belchers on earth. I can think of no vehicle that I despise more and when I am in any of these countries, I do my best not to get into any of them as I do not want to add to the pollution that these countries already suffer from. Now, there's an attempt at making these more efficient. Treehugger has this very interesting piece about a San Jose State University development of a hybrid solar-human powered autorickshaw: http://www.treehugger.com/files/2008/12/human-solar-powered-hybrid-electric-vehicle-unveiled-california.php
My feeling is that this very basic design could be improved easily or merely replicated anywhere else. Now, will some company in India take the callenge up? The target market includes India - Bajaj? TVS? Come on, guys!