By Lisa FriedmanDec. 20, 2022, 9:45 a.m. ET4 MIN READWASHINGTON — The Biden administration on Tuesday strengthened limits on smog-forming pollution from buses, delivery vans, tractor-trailers and other trucks, the first time in more than 20 years that tailpipe standards have been tightened for heavy-duty vehicles.The new rule from the Environmental Protection Agency is designed to cut nitrogen oxide from the vehicles by 48 percent by 2045. Nitrogen dioxide is a poisonous gas that has been linked to cardiovascular problems and respiratory ailments like asthma. The rule will require manufacturers to cut the pollutant from their vehicles starting with the model year 2027.