Mary E. Ahern, P.E., - Specializes in Traffic Engineering and Traffic Signal System Design and Optimization. As an Expert Witness, Ms. Ahern has experience in determining causes of vehicle accidents, investigating pavement markings, assisting in case direction and traffic solutions, preparing sight distance calculations and accident site photography analysis. She also teaches traffic engineering and geometrics as an adjunct instructor for Northwestern University.

Areas of Expertise:Red Light Cameras

Traffic Engineering Traffic Counts Traffic Warrant Studies Traffic Signal and System Design Video Vehicle Detection Audible Pedestrian Signal Design Emergency Vehicle Preemption Design Accident Analysis

Red and Amber Clearance Interval Calculations Accident Site Photography Accident Site Video Production Sight Distance Calculations Dilemma Zone Issues Procedure Development Sales Roadway Design