Union Road Transport Minister Nitin Gadkari has announced that owners of old diesel trucks and buses will be allowed to retrofit their vehicles with a low-cost emission-control device developed from an IIT-Delhi innovation. The device, priced at around Rs 4,000-5,000, can cut particulate matter emissions by up to 90% and nitrogen oxide emissions by 60%, bringing BS-III, BS-IV and older diesel vehicles close to BS-VI emission levels.