Transportation department officials say the eastbound lanes northwest of Columbia were opening Thursday morning. The westbound lanes were set to open Friday morning.
Transportation Secretary Janet Oakley says the project is opening after just 21 months of construction. It had been expected to take 36 months.
Work will continue throughout the summer and nighttime lane closures will be required at times. The final work includes asphalt paving, grinding the concrete roadway, guardrail work, and removal of the temporary barrier wall.