DTE Energy is continuing its street light improvement program in Dearborn, the company announced Wednesday. The next phase of work is set to start Feb. 4.

The work is part of a $4 million investment to improve street lighting service in various Southeastern Michigan communities. Work began in the summer of 2012 in Dearborn, and will continue through 2013.

DTE Energy will upgrade nearly 100 older street lights that are energized by “series circuits.” These streetlights pose problems because when one light goes out, other lights on the circuit can be affected. The upgrades—to high-pressure sodium from mercury vapor—will ensure that when there is a problem with one street light, other lights on the circuit will continue to operate.

To complete each phase of the project safely, DTE Energy will shut off power to impacted street lighting circuits for 30 to 40 days.

According to DTE, signs will be posted on streetlights that are affected by the upgrade work, and door hangers will be left at area homes and businesses to notify them that work is being done. Most of the work, which will continue through March, will be along Schaefer between Ford Road and Tireman.

Go to dteenergy.com/lights for project status reports. Or, for questions regarding the project, contact DTE Energy’s Community Lighting department at 800-548-4655.