Studies often include proposed traffic distribution for future conditions, origin/destination studies, travel demand modeling, microsimulation, examination of crash data, predictions of anticipated crash frequency using the Highway Safety Manual (HSM), traffic impact studies, traffic operations studies, traffic signal warrants, traffic analysis for maintenance of traffic phasing, pedestrian and bicycle safety studies, intersection/interchange design studies, and noise analysis. In addition to studies, traffic engineers prepare construction plans and specifications for traffic signals, traffic signal interconnect, Intelligent Transportation Systems (ITS), signing and pavement marking, passive and active pedestrian warning devices, and traditional and innovative intersection geometric design.