Colorado lawmakers will study whether to require snow tires or chains to drive on a mountainous stretch of Interstate 70 during spring and winter months, under a bill Governor John Hickenlooper signed into law yesterday. The intent of the bill initially was to make the tire requirements mandatory, but sponsors of the legislation couldn’t get enough support for the idea. Instead, a legislative committee will study the matter and issue recommendations when lawmakers convene for the 2016 session in January. Before the bill was turned into a study, the measure would’ve required non-commercial vehicles without four-wheel drive to have tires with snow-appropriate tread or else carry chains from November to May. The goal was to prevent traffic congestion from accidents. Opponents called the tire requirement difficult to enforce.