Passenger vehicles with inadequate tires have been identified as a major cause of delays and closures on I-70 traffic. The Colorado State Patrol says that 60 percent of congestion delays on I-70 are due to crashes. It is safe to assume that bald tires contribute to some of these car accidents. In addition, cars that lose traction on hills cause blocked lanes and closures that significantly contribute to travel delays.  Colorado’s traction law requires all tires to have at least 1/8″ tread depth.

The Passenger Traction Law is in effect Sept 1-May 31, regardless of current weather conditions. Learn if your tires meet the Traction Law specifications here.

Tire inspections are not required in the state of Colorado. Stopping cars at I-70 on-ramps to check tires is not a viable solution due to the traffic jams that action would cause. CDOT and Colorado State Patrol have recently implemented extensive public education campaigns around the importance of adequate tires on the I-70 corridor.


Overnight parking is allowed in the Dinosaur Lots. There is no set maximum number of nights, but cars there for an extended period and considered abandoned could be towed. The Dinosaur Lots are maintained by CDOT and patrolled by the Jefferson County Sheriff’s office. For more information, contact the Jefferson County Sheriff’s office (303-277-0211).


Federal law does not allow for limiting trucks on an Interstate based solely on time of day, day of week, or time of year. However, CDOT will use its authority to hold commercial motor vehicles when adverse weather combines with significant congestion to create public safety concerns.


Yes, the Colorado State Patrol does enforce the left lane law. When a road is two or more lanes and the posted speed limit is 65 MPH or greater, they will contact drivers that are using the left lane as a travel lane. If traffic is at a rate that the left lane is being used as a general traffic lane, they allow vehicles to use the left lane continuously to keep traffic flowing as much as possible.

The Colorado State Patrol does issue citations for unsafe tires. Because of the difficulty of seeing tires as a vehicle moves, this is not a violation seen until they contact a driver for a separate reason.

The winter season of 2014/2015 saw an increased focus by the members of the Colorado State Patrol Motor Carrier Safety Branch in identifying commercial vehicles violating the chain law codes. When that violation is observed, it is cited. There are other traction control devices that satisfy the requirements and sometimes those devices are not as visible as chains. An example of this would be the automatic sanders that a greater number of vehicles traveling the Interstate 70 corridor are using. 

Possible Solutions

Traffic on I-70 in both directions have reached levels that no longer allow for lane reversal as a strategy to address peak congestion. According to CDOT data, the backups in the single lane would be longer and more significant than the current backups in the peak travel direction. In addition, there are significant safety and cost implications of changing one direction of the interstate to a two direction travel highway. Here is a report from the exploration of the 2010 Zipper Lane concept.


Transitioning travelers from their cars and into buses can absolutely make a dent in weekend traffic, although buses alone won’t solve I-70 congestion.  This is due to the sheer number of buses that would be required to move weekend travelers, and the fact that today’s buses don’t travel up steep grades at speed.  CDOT and several ski areas are partnering to operate Snowstang, a weekend bus direct from the Denver area to resorts. CDOT’s Bustang and Pegasus provide service seven days a week.

Hazard Materials

The Hazmat routing through EJMT is controlled by both CDOT and the State Patrol.  Hazmat routing is governed by both alternate routes available, as well as risk to the travelling public and the facility.  Presently, hazardous material is routed over Loveland Pass, except in cases of inclement weather when it is routed through the tunnel.  The risk of an accident is higher when the hazmat is mixed with regular traffic-so the trucks are staged and let through at the top of the hour. Some types of Hazmat are never allowed through the tunnel-regardless of whether Loveland Pass is closed.  Examples would be explosives or extremely corrosive chemicals.  The rules were last updated in 2008, and to change them is a public process that takes about 2 years, once initiated.  Aside from the security and safety of the tunnel, local governments weigh in on the practicality of routing hazardous cargo through their communities, and evaluate other potential threats–like chemical spills in watersheds.

Some other tunnels in Colorado allow hazardous materials to pass-an example is the Hanging Lake Tunnel in Glenwood Canyon.  However, there is no reasonable alternate route available for that tunnel, so the risk is accepted.  Few complex tunnels nationwide allow unfettered Hazmat access.  CDOT and the State Patrol are charged with balancing transportation needs with safety and security of the travelling public and the infrastructure–and it is through that balance that hazardous material routing maps are created.


The Colorado Department of Transportation has the ultimate authority to close the interstate.

Traffic metering goes into effect during very high-volume times at the Eisenhower Johnson Tunnel on the eastbound approach.  Metering controls the flow of traffic eastbound towards the Eisenhower Tunnel so traffic does not back up in the tunnel, causing potential safety issues.

Stay Informed

We offer two options to keep I-70 travelers informed of current
activity and future plans for the I-70 mountain corridor.

I-70 Alert

The I-70 Alert e-newsletter keeps you up to date on the big picture, including current and future policies, projects, studies and initiatives aimed at fixing I-70. 
Frequency: Quarterly eBlast eBlasts keep you informed on potential impacts and opportunities related to your trips on I-70. These short updates contain timely info on construction projects, new transit options, CDOT winter operations and strategies for beating the crowds.
Frequency: An average of 1-2 times/month