A busy section of Colorado's highway system through central Denver was shut down for maintenance for several hours Friday.

The northbound I-25 ramp to westbound I-70 closed for repairs at about 9:45 a.m., according to the Colorado Department of Transportation. It reopened about 12:30 p.m.

The ramp is part of the mousetrap, one of the busiest sections of highway in the state.

CDOT says the ramp needed an emergency expansion joint repair.

Kieran Nicholson: 303-954-1822, knicholson@denverpost.com or twitter.com/kierannicholson