WisDOT | Mitchell Tunnels Lighting + Controls Assessment

Client: Wisconsin Department of Transportation
Status: Completed February 2016
Location: Milwaukee County, Wisconsin
Total Cost:
Project Fee: $75,000
Services Provided:
  • Tunnel Lighting Assessment
  • Lighting Concept Report

SINGH provided a Lighting and Control System Assessment of the existing Mitchell Interchange Tunnels in Milwaukee County as part of the WisDOT Statewide ITS and Electrical Systems Design Master Contract. The Mitchell Tunnels Lighting System, a series of three tunnels, was constructed in 2012. WisDOT observed operational issues with lighting levels within the tunnels. SINGH provided lighting and control assessments of three tunnels to investigate the cause for control malfunction. The scope included an evaluation of the complete system to minimize operation and maintenance costs and a cost/benefit analysis to replace existing HPS luminaires with LED tunnel luminaires.

The assessment found that the location of the photometer, which senses the ambient lighting condition outside the tunnels were incorrectly located. These photometers send a signal to the control system to determine the light level inside the tunnel based on exterior conditions.

SINGH made recommendations to WisDOT based on the investigation including:

  • Reduce the number of daytime light levels from six to three to provide a more consistent driving experience and extend the life of the lamps and ballasts
  • Re-aim the tunnel luminaires to optimize the system
  • Replace existing photometers with next generation model that can be mounted closer to the tunnel entrances to provide more accurate readings
  • Replace HPS fixtures with LED for lower light levels and cost savings

« Back to Experience