nhk world's yuko funazaki has more. >> reporter: rajshahi is a city in northwest bangladesh. ordinary people rely on manpowered rickshaw taxis to get around. rickshaws carry only about two adults. they travel at the speed of a bicycle. recently a new type of vehicle is in the fast lane. it's the ultra rickshaw. the high-tech vehicle runs on electric instead of gasoline. on the streets, they're becoming more and more common. it's electric, so there's no gas emission, it's quiet, relatively stable and smooth, it's quite comfortable. the vehicle runs at a maximum speed of about 50 kilometers per hour. it can carry more passengers than man-powered rickshaws. and it can travel more than 130 kilometers on a fully charged battery. the battery is the main reason for the surge in popularity. it's easy to charge overnight from a regular wall socket. >> translator: i bought this auto rickshaw about $1,600 a year and a half ago. the vehicles are more expensive now. it's really good to have my auto rickshaw. now i can go anywhere, any time. >> reporter: this factory in the capital dhaka a