Highway 93, the Diagonal, and the Turnpike: why Boulder commuters collect rock chips
The Boulder-area roads most likely to chip your windshield, and what to do when it happens.
Ask anyone who commutes from Boulder to Golden or the Denver Tech Center and they will have a Highway 93 story. The two-lane stretch between Boulder and Golden carries quarry and construction traffic, sits in a wind corridor that sweeps grit across the road, and gives you very little room to back off from the truck ahead.
The usual suspects
- Highway 93 south. Gravel and aggregate trucks, high winds, and narrow shoulders. The most common source of chips we repair on Boulder cars.
- The Diagonal (Highway 119) to Longmont. Fast, straight, and busy with trucks. Chips here tend to hit high on the windshield.
- US-36, the Boulder Turnpike. Winter sanding and heavy traffic. A chip picked up here in January rarely stays small.
- Boulder Canyon and Lefthand Canyon. Rockfall debris and freshly plowed grit after every storm.
What to do in the first few days
Cover the chip with a piece of clear tape to keep dirt and moisture out, avoid blasting the defroster, and get it repaired within a week. A fresh, clean chip repairs almost invisibly. One that has been through a few freeze-thaw cycles on a North Boulder driveway often will not.
Why Boulder cars need calibration more often
Boulder has one of the highest concentrations of Subarus and EVs in the state. Nearly all of them carry windshield-mounted cameras for lane keeping and automatic braking. If your chip turns into a replacement, plan on calibration being part of the job. It is not optional on these vehicles.