TDM stands for transportation demand management. TDM is a way of using existing infrastructure to travel in a way that reduces congestion – it simply means redistributing the demand for transportation networks in space and time. That can mean shifting a certain number of commuters away from driving alone during peak rush hours by a number of means, from telework or flex hours to transit, biking, or carpooling. Because it doesn’t require building new infrastructure, it’s a cost-effective way to make an immediate change in traffic congestion and the impacts congestion has on individual commuters.