Colorado Road & Driving Conditions Colorado Traction Law Colorado's traction law applies on I-70 from Dotsero to Morrison (mile markers 133–259), generally Sept 1–May 31 and during winter weather.
Code 15 — Traction Law (SB25-069)
Requirements now depend on drivetrain. 2WD vehicles must have chains or an approved traction device (ATD) — snow, M+S, or 3PMSF tires alone no longer qualify. 4WD/AWD can comply with chains, an ATD, or 3PMSF/M+S/all-weather tires with at least 3/16" tread.
Code 16 — Chain Law
Chains or approved traction devices required on all vehicles regardless of tire type or drivetrain.
Penalties: up to $500 + $79 surcharge; $1,000 + $157 if you get stuck and block the road.
Full traction law details → Key Colorado Routes I-70 Mountain Corridor
Primary ski route. Eisenhower Tunnel (11,158 ft) and Vail Pass (10,662 ft) can have snow when Denver is sunny.
I-25 Front Range
Denver's main north-south artery. Overpasses and bridges freeze first during winter storms.
Mountain Passes
Loveland Pass (US-6), Berthoud Pass (US-40), Independence Pass (CO-82). Steep grades, sharp curves, seasonal closures.
Seasonal Tire Tips Winter (Oct–Apr)
Winter or 3PMSF all-weather tires recommended for I-70 mountain travel. All-seasons alone may not cut it in heavy snow.
Summer (May–Sep)
Check pressure monthly — Colorado's elevation changes cause fluctuations. Replace tires under 4/32" before road trip season.
Year-Round
Rotate every 5,000–7,500 miles. Inspect regularly for pothole and debris damage common on Colorado roads.
Quick Answers Are all-seasons enough for I-70?
For 4WD/AWD, all-seasons (M+S) with 3/16" tread meet the Traction Law — though winter or 3PMSF tires grip far better. For a 2WD, tires alone no longer qualify under SB25-069: you need chains or an approved traction device.
When is the traction law enforced?
CDOT activates it based on conditions, typically September through May on the I-70 mountain corridor.
How often should I check conditions?
Check before departing. Mountain weather changes in minutes — during storms, check hourly.
King's Custom Tires 4101 Colorado Blvd, Denver CO
Mon–Sat 8am–6pm
(303) 292-3589
Free tread depth inspections. Winter tires and all-weather tires in stock for same-day install. We also mount customer-supplied tires.
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