The SmartLane is getting faster.

The Ohio Department of Transportation announced Thursday that it will raise the speed limit on the SmartLane, which opens in the left shoulder of eastbound Interstate 670 when traffic slows from an average of 55 mph to 45 mph.

The new speed limit will take effect Monday.

ODOT opened the SmartLane, the first of its kind in Ohio, last fall after years reconstructing I-670 and its interchange with I-270 near Easton.

Most of the time the speed limit will remain 65 mph on eastbound I-670. Traffic monitors track how fast vehicles are moving, though, and they can open the SmartLane when they slow below 45 mph.

When the lane opens, the speed limit on the entire stretch of highway between Downtown and I-270 is reduced to 45 mph. That will change to 55 mph next week for all lanes.

Digital signs over the highway display when the lane is open.

At times, ODOT still could lower the speed limit below 55 mph on the entire length of eastbound I-670 or in smaller stretches to deal with traffic backups or changing road conditions.

Originally, ODOT chose the 45 mph speed limit because officials were worried about sight distance around I-670’s curves. The agency’s data show the average speed when the lane is open is 55 mph, and ODOT installed another camera near the 5th Avenue curve to monitor traffic backups there, said Brooke Ebersole, an ODOT spokeswoman.

“The biggest thing I want to stress is to remember this is a pilot project,” she said. “We were erring on the side of caution at first to see how this was going to work.”

ODOT spent about $60.5 million on the SmartLane and interchange. When the two opened, travel times on that crowded stretch of highway fell dramatically and have become more predictable.

The average commute time on I-670 dropped from about 10 minutes before construction started to about five minutes now.

"This approach allows us to be proactive in keeping drivers safe," ODOT Director Jack Marchbanks said in a statement. "The agile technology of the SmartLane, combined with our ability to adjust the speed limit, enables us to truly manage traffic, not just monitor it."

rrouan@dispatch.com

@RickRouan