MDOT Implements New Type D Light Technology

Effective with the July 6, 2007 letting, MDOT will implement a new specification on all their projects that requires lights on plastic drums be Type D, 360-degree warning lights.

This change in the warning light requirement is the result of an ongoing cooperative effort between MITA and MDOT to improve the overall quality and effectiveness of the nighttime delineation of work zones. MITA and MDOT agree the new 360-degree light will address MDOT’s concerns with lens alignment, a common problem often cited with the outgoing flat lens technology. When misaligned the flat lens lights often appear to be off or display significantly reduced intensity. The new Type D, LED lights are capable of emitting light in 360-degrees while sustaining constant brightness without an alignment concern.

“This new technology combined with industry’s commitment to light maintenance should result in immediate improvements in the quality of work zone delineation at night,” said Glenn Bukoski, MITA’s vice president of engineering services. “This will be a cultural change for some of us as our commitment to a higher level of light maintenance will involve not only the traffic control suppliers but also prime contractors who will need to timely notify these suppliers when light maintenance or replacement may be required within the planned maintenance schedule.”

For all MDOT projects let prior to the July 6, 2007 letting, the flat lens technology will be in affect per the contract documents.

To view the MDOT Special Provision for Lights on Traffic Control Devices that specifies the Type D, 360-degree light effective with the July 6, 2007 letting, click here.

If you have any questions contact Glenn Bukoski at, or Doug Needham at, or call them at the MITA office at 517-347-8336.