I-70 at Route 51 Interchange

Changing Traffic Restrictions to Take Effect July 15

Beginning Tuesday, July 15, 2025, traffic will shift onto the newly constructed Route 51 northbound (NB) bridge, marking a major milestone in the ongoing Diverging Diamond Interchange (DDI) project.

This shift will introduce the final DDI movements with single-lane traffic in each direction across the two new bridges carrying Route 51 over 
I-70. Outside lanes in both directions will be open to traffic, while inside lanes will be closed. Temporary traffic signals will remain in place during this phase to manage traffic flow and ensure safety.

As part of this change, I-70 single-lane restrictions will be moved to the opposite side of the highway to allow crews to begin reconstruction on the remaining lanes and inside shoulders.

Click here to enlarge image.

See work zone mapping here. Tips for your safety and the safety of highway workers can be found here.

2025 Construction Overview

In 2025, construction will be focused on completing the reconstruction of eastbound and westbound I-70, construction of the northbound Route 51 bridge over I-70 and the Diverging Diamond Interchange (DDI), and reconstruction of southbound Route 51.

Planned construction phasing includes:

I-70 Mainline

In April, westbound traffic was shifted onto temporary widening while the lanes and medians are reconstructed.

In July, westbound traffic will remain on temporary widening and eastbound traffic will be shifted onto newly-constructed westbound lanes while the new eastbound lanes, on/off ramp acceleration/deceleration lanes, and median are reconstructed.

The mainline construction is expected to be complete in 2025.

Route 51 Diverging Diamond Interchange
Construction will include the completion of the new northbound Route 51 bridge over I-70. 2025 construction will also include all ramps within the DDI pattern, and opening of the DDI, including permanent signals and a single lane of traffic in each direction on Route 51 using new bridges.

Route 51 Corridor
Route 51 southbound will be fully reconstructed in addition to left-turn standby lanes at intersections. Signals will remain at Route 981/ Relocated Finley Rd. and Concord Ln. Temporary signals along the corridor will be replaced with permanent ones this winter.

See work zone mapping here. Tips for your safety and the safety of highway workers can be found here.

Construction at the I-70/Route 51 Interchange began in late 2022 and is expected to continue through 2026. Track construction progress with updated construction photos.