Colorado Highway by Drew Shively

Is Colorado Traffic Driving You Nuts? You Might Be Driving Wrong.

With Colorado’s population continuing to grow at a rapid rate, and with traffic volume outpacing infrastructure improvements, roadways throughout the state are becoming more and more crowded. Congested highways and surface streets used to be a mere “rush hour” annoyance, but Colorado’s roadways now seem to be congested no matter what time of day it is.

Whether driving to the ski slopes or the office, with increased congestion comes escalating tension and frustration, particularly with behavior of other drivers. We’re convinced that they’re “doing it wrong” – but are they? A review of Colorado’s traffic guidelines provides some insights into how to handle certain driving situations, and the answers may surprise you.

The Left Lane is Only for Passing (Unless Traffic is Too Congested to Merge Right)

We see them all the time – the slowpokes who seem to be just hanging out in the highway’s left lane, and who refuse to move over for the traffic stacking up behind them. It’s as if they think the left lane was lined with velvet ropes and personally paved just for them. You’ve probably thought to yourself, if only they would stop pacing the vehicle next to them and move over, highway traffic could easily move swiftly along. The slowpoke who seems content to stay in the left lane surely believes the vehicles stacked up behind him are “tailgating” and are simply rude, aggressive drivers.

However, in Colorado, snoozing in the left lane is only acceptable and lawful on certain roadways, and under certain circumstances. Generally, drivers are supposed to treat the left lane as a “passing lane” and right lanes as “non-passing lanes” when the speed limit is 65 mph or more.

This means that when the speed limit is at least 65 mph, drivers should be in the left lane only if they are passing another vehicle, or if traffic is so congested that it doesn’t allow them to merge safely into a non-passing lane. After passing a vehicle from the left lane, the driver should then move over into one of the right lanes. This prevents traffic from backing up in the left lane (and other drivers’ blood from boiling) and allows faster-moving traffic to flow around slower-moving traffic.

Although Colorado’s left-lane law has been on the books since 2004, it seems few drivers either understand or appreciate its significance, even though the law is “intended to help improve both traffic flow and safety.” As Governor Bill Owens explained when he signed the bill into law, “[v]ehicles traveling below the speed limit often create real traffic hazards if they are in the left lane.” He also said, “Reserving the left lane for passing will improve safety as well as traffic flow.”

Additionally, the then-Chief of the Colorado State Patrol, Mark Trostel, explained that, “When slower moving vehicles occupy the left lane, they can cause traffic jams and frustration.” He concluded that, “This new law should help reduce incidents of aggressive driving, especially during high-volume traffic periods.”

If safety from aggressive drivers isn’t reason enough itself to keep you from “left-laning,” know that hogging the left lane could get you pulled over and your vehicle searched. At least, that’s what happened in U.S. v. Mora-Alvarez, in which a Colorado state trooper observed a vehicle driving on Interstate 70 in the left lane without passing.

The trooper pulled the vehicle over because it was “traveling in the left lane, not passing, just kind of hanging out.” During the traffic stop, the trooper spotted a variety of things that eventually led to a search of the vehicle, which is where drugs were discovered. Although the trooper initially declined to issue a citation for the left-lane violation, the suspect was ultimately arrested for possession of drugs after his vehicle was searched, which likely would not have happened if the suspect wasn’t left-laning.

So, your frustration with slowpokes in the left-lane is not only warranted, it’s supported by Colorado’s traffic laws. Such frustration does not justify aggressive driving, of course, but the law in Colorado does require slowpokes to move over for faster-moving traffic behind them.

Passing on the Right is Legal (But Not Necessarily Safe)

Perhaps you’re inclined to pass left-laners from a right lane, and although it is technically legal in certain circumstances, care and consideration should certainly be exercised when doing so. We’ve all seen it, a frustrated driver in the right lane zooming past traffic that is backed up in the left lane when suddenly a vehicle ahead switches lanes or merges onto the highway, which almost results in an accident.

Although speeding is illegal, it is permissible at times to pass a vehicle on the right while on the highway, provided the highway has unobstructed pavement not unoccupied by parked vehicles and is marked for two or more lanes in each direction of travel. However, if drivers would simply use the left lane as intended (i.e., as a passing lane), it would be unnecessary for drivers to pass on the right, which would make our highways safer.

Merging Lanes (and Differing Philosophies)

Another common experience on congested Colorado highways is the reduction of lanes from three to two, or from two to one. In anticipation of the lane reduction, it is typical for vehicles in the merging lane to move over to the continuing or non-merging lane well in advance. Having done so, we fume at the vehicles that race ahead in the merging lane and then “cut” into the continuing lane just as the merge lane ends. If only the “Late Mergers” would stop cutting the line and wait their turn like everyone else, we think, then traffic congestion and everyone’s blood pressure could be reduced.

Well, believe it or not, the driver who is actually driving correctly is the Late Merger. Yes, although frowned upon when you’re in line for a ride at Elitch’s or the checkout at King Soopers, “cutting-the-line” is actually the preferred method for merging at construction zones, lane reductions, and onto highways in Colorado.

In fact, it appears that a campaign has been underway in Colorado for several years to educate drivers on the proper method for merging, where one lane of traffic intersects with another. As early as July 2013, the Colorado Department of Transportation (CDOT) posted a comment and cartoon video to its Facebook account, encouraging “drivers to use all available lanes until the final merge point. Then, signal and take turns merging into the single work zone through lane.” CDOT explained that this approach is “a safer, more courteous, and more efficient way through cone zones.”

Late Merge (AKA “The Zipper Method”)

A year later, in September 2014, CDOT posted another comment and video on its Facebook account, stating, “When merging into traffic, be sure to use the Late Merge or the Zipper Method.” According to CDOT:

Studies have shown the Late Merge to be the most effective way to merge into traffic to reduce delays and handle road rage. In classic lane mergers, drivers will merge early into the next lane. When traffic is high, this normally contributes to congestion and the frustration of drivers. If drivers will use the entire roadway then take turns merging from the closed lane into the open one, delays will be reduced up to 35%. This is why it is called the Zipper Method.

The zipper method is easier than it sounds – merging and non-merging drivers simply stay in their respective lanes until the two lanes begin to intersect. At that point, drivers in the respective lanes take turns either going straight or merging from the closed lane into the continuing lane (just like how the teeth of a zipper “zip up”). When merging early, drivers leave a lane unused and traffic behind the merge point backs up.

Here’s the CDOT video explaining this procedure:

Especially in light of the ever-increasing traffic in the metro and mountain areas, it’s increasingly important to understand and respect all of Colorado’s traffic laws. I hope you’ve found this article enlightening. Maybe it can even help you win a bet or two.

If you’ve been involved in an auto accident and you’d like to discuss your situation with an attorney, please contact me or any of the other attorneys at Proctor Brant to schedule a consultation.