A new tool from non­prof­it RMI and a con­sor­tium of part­ners includ­ing Trans­porta­tion for Amer­i­ca and the Nation­al Resources Defense Coun­cil “draws on for­mu­las sourced from decades of proven sci­en­tif­ic lit­er­a­ture to deliv­er detailed, com­mu­ni­ty-spe­cif­ic induced demand fore­casts with the click of a but­ton.” The State High­way Induced Fre­quen­cy of Trav­el (SHIFT) Cal­cu­la­tor “gives advo­cates the tools they need to instant­ly show the real impacts of pro­posed high­way expan­sions in their com­mu­ni­ties,” writes Kea Wil­son, pro­vid­ing a valu­able resource for show­ing the real-world impact of the well-doc­u­ment­ed but poor­ly under­stood phe­nom­e­non of induced demand.

“Sus­tain­able trans­porta­tion advo­cates and for­ward-think­ing pro­fes­sion­als alike have known since at least 1932 that expand­ing high­ways to cure con­ges­tion almost always has the oppo­site effect,” writes Wil­son, but “many of them haven’t been able to quick­ly quan­ti­fy exact­ly how much addi­tion­al dri­ving a spe­cif­ic project would encour­age, or exact­ly how much all those new vehi­cle miles trav­eled will exac­er­bate the cli­mate cri­sis — until now.”

The tool comes at a cru­cial time, with bil­lions of dol­lars for road fund­ing promised in the fed­er­al infra­struc­ture bill. The cal­cu­la­tor’s cre­ators hope it will help state DOTs devel­op more accu­rate pro­jec­tions that show the true costs and impacts of road widen­ing.