Researchers: Gene Hawkins, Jeff Miles
The term “lighting curfews” refers to the concept of turning off or reducing the amount of roadway lighting during certain portions of the night.The term “lighting curfews” refers to the concept of turning off or reducing the amount of roadway lighting during certain portions of the night when traffic volumes drop off. The TxDOT Highway Illumination Manual describes the concept of lighting curfews, but it does not give any criteria for when to implement them. This research project will evaluate the relationship between safety and lighting throughout the nighttime periods and develop criteria and guidelines for implementing lighting curfews. Research activities include the identification of previous research on the topic and surveys of other agencies, identification of existing TxDOT lighting characteristics, field measurements of lighting performance, a safety analysis of crashes with and without lighting as a function of time of night and traffic volume, a visibility assessment at selected sites, identification of other technical and non-technical issues associated with lighting curfews, a feasibility assessment of lighting curfews including the identification of benefits and costs, and a field evaluation of the preliminary lighting curfew guidelines. The final guidelines developed by this project will be prepared for inclusion in the Highway Illumination Manual and may include options such as turning off lighting at specific times/volumes, trimming lighting, or dimming lighting.
The nighttime lighting evaluations will evaluate the amount of light present in the roadway environment during various hours of darkness to assess the contributions of roadway lighting, vehicle lighting, and ambient lighting to overall roadway visibility. Both horizontal and vertical lighting measurements will be made.