Screen grab from CDOT's live streaming video system shows eastbound traffic at a standstill at 6:15 pm Sunday stretching down the Straight Creek Grade waiting on the west side of the tunnel for traffic to clear.

CDOT stopped eastbound traffic from entering the Eisenhower-Johnson Memorial Tunnels several times Sunday night due to heavy traffic on the east side backing up into the tunnel.

The practice, called “metering,” was started late afternoon on Sunday and lasted until CDOT announced at 8:38 p.m. that it had ended. Snowy conditions added with the already high number of vehicles making the drive resulted at times in standstill conditions at the Continental Divide.

When this occurs, CDOT uses 20-minute traffic stops on the west side, which it calls “metering,” in order to prevent vehicles from standing idle inside the tunnel. This is done to maintain emergency access in the event of a fire, medical emergency or other need to crews to gain access to the tunnel.

When CDOT releases the traffic, typically it catches up to the back end of the traffic jam going back to Denver, which it notes results in no actual net increase in delay for travelers.

Photo from a CDOT traffic camera looking east outside the Eisenhower-Johnson Memorial Tunnels shows the backup headed down toward Silver Plume nearly reaching the tunnel exit at 4:30 p.m. Sunday.

Looking down from U.S. 6 on the east side of Loveland Pass toward the Eisenhower-Johnson Memorial Tunnel. CDOT Photo.

CDOT Traffic Alert

Typically, CDOT expects Saturday traffic to taper off by 10 a.m. but today, westbound traffic was still heavy in the afternoon.

Eastbound traffic volume is expected to be high from 9 a.m. to 7 p.m. both Sunday and Monday. During these times, it drivers should anticipate that there will be periodic traffic stoppages at the west portal to the Eisenhower-Johnson Memorial Tunnels to prevent idling traffic from backing up into the tunnel.

CDOT advises motorists to be prepared for heavy congestion, take U.S. 285 or another alternate route or travel in the early morning or late evening hours.

The uprecedented January jams may have been caused by a ‘perfect storm” scenario of other external factors, CDOT managers said.

Go to the Summit County Citizens Voice to see the entire report.

The Variable Message Sign on I-70 eastbound at Copper Mountain had this message on Thursday night. Image downloaded from CoTrip.org.

Motorists crossing the Continental Divide at the Eisenhower-Johnson Memorial Tunnel on Interstate 70 may soon be getting more specific warnings about tunnel closures during heavy traffic, following Saturday’s record three hours of traffic stops to keep idling cars out of the tunnel.

The Colorado Department of Transportation is coming up with different wording for the overhead lighted signs called Variable Message Signs that would make drivers more aware that they might have to come to a stop on the highway while traffic jams ahead clear up.

When CDOT needs to shut off traffic flow through the tunnel, the message boards will be modified to say something like “20 minute traffic stops at tunnel; 4 hours+ to Denver,” said CDOT spokesman Bob Wilson.

“This is just a draft message – we still need to discuss the exact wording and some protocol – but we’re moving forward with the metering messaging, something that we haven’t done in the past but will now do.,” Wilson said.

On Saturday, when CDOT imposed seven traffic stops in the eastbound lanes outside the tunnel entrance totaling three hours over a five-hour span, the VMS messages said: “Heavy traffic ahead; expect delays.” That wasn’t specific enough to prompt many drivers to delay their ascent up the steep Straight Creek grade that approaches the tunnel from the west side. The line of stopped cars wound down to Silverthorne and a number of motorists opted to detour around on U.S. 6 via Loveland Pass.

CDOT has a safety-driven policy of not allowing traffic jams to back up into either bore of the 1.7-mile tunnel complex – the highest point in the entire U.S. interstate highway system at 11,158 feet above sea level.

Image from Google Earth looks east up the Straight Creek valley from over Silverthorne toward the Eisenhower-Johnson Memorial Tunnel complex. This is the grade where traffic was stopped seven times on Saturday.

The concern, says Mike Salamon, CDOT’s tunnel superintendent, is that emergency responders would not be able to get to a vehicle fire, accident or medical problem inside the tunnel if traffic is at a dead stop from end to end. The two-lane bores have no shoulders to drive along.

The practice is instituted when downhill traffic slows and the line of traffic starts to back up to within a mile of the tunnel portal. To avoid having stopped cars inside, CDOT prevents more traffic from entering the other side.

The longest stoppage on Saturday lasted 40 minutes. The average of all seven closures was 22 minutes.

CDOT calls the practice “metering” traffic. But as opposed to ramp meters that dribble one or two cars at a time down an entrance ramp onto a busy freeway, metering at the tunnel means full stop until traffic jams downstream break up. How long that takes depends on the circumstances. Salamon said drivers detouring over Loveland Pass actually made the closures last a bit longer as they added to the jam headed down toward Silver Plume.

Wilson said CDOT hadn’t been as specific on its VMS messages before now. One problem is that CDOT often needs to convey several messages to drivers during bad weather. Primarily, it is obligated to inform truckers when the chain law is in effect, since failure to use chains can incur heavy fines for trucks. Truck accidents or slides are a major contributor to congestion on I-70 in the winter.

“A couple of the VMSs have to remain for chain law messaging, so not all our signs will be able to have the tunnel stop information when the chain law also is in effect,” Wilson said.

The message on the VMS on I-70 eastbound at Silverthorne notified truckers of the chain law over Loveland Pass.

Between Copper Mountain and the tunnel’s eastbound entrance, CDOT has five VMSs installed over the eastbound lanes. But two of them are on the uphill grade, beyond the point where motorists can change their minds about pulling over in Silverthorne.

CDOT’s CoTrip.org web site has a map on which you can read in real time the current messages displayed on any VMS in the state. You can access that by clicking here, then choosing the “Signs” tab on the right.

Wilson said CDOT will also make more use of CoTrip.org and its 511 traffic information phone line to disseminate information about tunnel “metering” closures. One problem inherent in stopped traffic is that CDOT’s roadside devices that monitor traffic speeds don’t calculate information from stopped vehicles. The devices need to track vehicles from one point to another in order to calculate speed and travel times for the message boards. So accurate messages about how long the drive to Denver will take can’t be obtained during tunnel stops.

CDOT uses several different devices to electronically read a vehicle’s toll transponder to calculate travel speeds and times. Some were featured here in a recent Inside Lane slide show presentation on high-tech roadside equipment.

The east portals of the Eisenhower-Johnson Memorial Tunnel on Interstate 70.

Blowing snow and resulting traffic backups on Interstate 70 on Saturday prompted seven separate stoppages totaling three hours at the westbound entrance to the Eisenhower-Johnson Memorial Tunnels under the Continental Divide.

It brought an avalanche of driver complaints and a review by the Colorado Department of Transportation of the messages it puts on its electronic signs.

But don’t expect the practice of halting traffic to end. It’s all about your safety.

“It’s very much to assure ourselves that we can respond to an emergency in there,” said Mike Salamon, CDOT’s superintendent at the tunnel. The 1.7-mile, two-lane bores have no shoulders and no way for emergency vehicles to maneuver around stopped cars. “How could anybody ever explain watching a ski bus burn in there and we couldn’t get to it? When traffic starts to fill up to about half the tunnel, we shut it down.

“This is an absolute safety action,” said Salamon. “We have never had a fatality inside the tunnel, due in part to some of the things we do like this.”

The traffic stops, which CDOT calls “metering” traffic through the tunnels, happened Saturday between 3:30 and 8:30 p.m. They were prompted by heavy traffic backups originating near the Silver Plume grade that slowly backed the line of cars up the hill to the U.S. 6 Loveland Pass interchange, within sight of the tunnel.

“Traffic started queuing somewhere down around Silver Plume probably due to blowing snow and probably some inexperienced drivers,” Salamon said. “Eventually it came to a dead stop and began backing into the tunnel. If we didn’t stop traffic from entering, it would have continued to back up clear through the tunnel and down the west approach. We have never allowed that to happen.”

As annoying as the stops might be for drivers stuck on the steep grade of the Straight Creek approach – especially when it is snowing and it might be difficult for uphill vehicles to regain traction – CDOT says the traffic stops will continue whenever there is a risk of a traffic jam bringing cars to a dead stop inside the tunnels. And since the stalled drivers merely catch up to the traffic jam on the other side once CDOT releases them, it says there is no added delay for drivers. They don’t get home any later than they would have.

“If we had just let nature take its course, you still would have been stuck downstream, but I wouldn’t have done it to you,” said Salamon.

Looking down from U.S. 6 on the east side of Loveland Pass toward the Eisenhower-Johnson Memorial Tunnel. CDOT Photo.

CDOT stops cars from entering the eastbound tunnel once a back-up of downhill traffic on the Clear Creek side works its way back to the Loveland Pass interchange, about a mile below the portal. When that happens, CDOT stops traffic short on the steep grade of the Straight Creek valley on the west side. Traffic already moving through the tunnel at the time of the stoppage adds to the back up and, on occasion, vehicles sometimes end up idling at a stop inside the tunnel.

With a nod to you highway purists out there and for the education of casual readers, the eastbound tunnel that was affected by Saturday’s closure is actually the Edwin C. Johnson Memorial Bore, which opened in 1979. “Big Ed” Johnson was a longtime Colorado governor and U.S. Senator who was instrumental in getting I-70 extended west from Denver across to Utah. I-70 as originally proposed was to have ended at Denver’s Mousetrap interchange with Interstate 25. The westbound tunnel is the Eisenhower Memorial Bore, named for President Dwight Eisenhower, who signed the interstate highway system into law and who made Denver and Colorado his frequent summer getaway. It opened in 1973.

At a maximum elevation of 11,158 feet at the west portals, the Eisenhower-Johnson Memorial Tunnel complex is the highest point on the entire U.S. interstate highway system. There is an excellent account of the tunnels’ history at the I-70 page on Matt Salek’s Highways of Colorado web site.

CDOT’s collection of tunnel facts and figures is here.

Salamon said air quality isn’t much of an issue even if traffic does get stopped in the tunnels. Each of the 28 exhaust fans in the tunnel system is capable, he said, of moving a half-million cubic feet of air per minute.

“We can create hurricane-force winds in our air duct, approaching 90 miles per hour,” he said. That would easily clear any deadly carbon monoxide buildup from the tunnels.

The principle risk is an event like a vehicle fire, accident or medical problem inside the tunnel when traffic is dead stopped. He said the tunnels average two vehicle fires a year, some of them major conflagrations.

“The main reason is you can imagine what if we had an accident, a fire or a medical assist halfway through the tunnel and we have traffic at a dead stop,” he said.

A few times, claustrophobic drivers have come to a stop inside and jammed up traffic. Salamon said CDOT workers have had to drive those cars out on their own.

Saturday’s seven metering events were noteworthy for their number and duration. Salamon said CDOT doesn’t have readily available records to total the number of stoppages over time, but Saturday’s were among the worst.

One stoppage alone lasted 40 minutes. The average for all seven was 22 minutes.

“It is happening with more frequency as we see more and more traffic,” he said. “It can happen just as easily in the summertime.” Summer traffic counts are generally higher at the tunnel. July and August usually have the highest traffic counts, followed by March and January. The highest hourly traffic count in one direction was 3,450 vehicles – essentially 100 percent of capacity.

You can look at monthly traffic counts at the tunnel here.

“I talked to a few very very angry folks,” Salamon said. “But with the volume of traffic and the weather conditions, it’s going to happen and I don’t know of any way to solve it.

“If we had allowed traffic to back into the tunnel, during that one time it would have taken 40 minutes to get thought the tunnel, and that is unacceptable,” Salamon said.

On Saturday, the line of cars snaked back down to Silverthorne, and Salamon said some drivers opted to bail on I-70 there and take Loveland Pass instead. That eventually added to the congestion problem as those drivers re-entering I-70 beyond the tunnel delayed the break-up of the traffic jams that were causing the stoppages on the west side

CDOT said its variable message signs in Summit County approaching the hill to the tunnel carried the words, “Heavy traffic ahead; expect delays.”

CDOT officials met Wednesday to discuss the Saturday events and, among other things, whether the messages should have been more specific, such as “Periodic tunnel closures ahead; consider delaying your trip.”

There is no practical fix for the problem. Even adding a third bore or widening the tunnels wouldn’t prevent the traffic backups on the two-lane downhill highway segments, and widening the entire highway is both prohibitively expensive and politically unpopular. CDOT has added ramp meters to some entrance ramps in an effort to prevent clogs at interchanges, and has added ski-season courtesy patrols to clear stalled or wrecked vehicles. Its dynamic message signs can help drivers decide whether to delay their departures until there is less traffic.

Long-range, planners are looking at lane additions in selected segments and building a transit system of some sort along the corridor from Denver to as far as Vail.

A new record for August was set at the Eisenhower/Johnson Memorial Tunnels when 1,164,595 vehicles traveled under the Continental Divide. That’s 41,982 more vehicles than in August 2008.

Numerous other tunnel records were set last month, including:

* Highest 24-hour traffic count of 50,918 set on Sunday, August 2
* Fifth highest 24-hour traffic count of 50,117 set on Sunday, August 9
* Highest three-day weekend count of 148,300 vehicles set Friday, August 7 through Sunday, August 9
* Second highest three-day weekend count of 146,930 vehicles set Friday, July 31 through Sunday, August 2
* Second highest eastbound/westbound hourly count of 4,629 vehicles set at 1 p.m. on Sunday, August 2
* Ninth highest eastbound/westbound hourly count of 4,499 vehicles set at 3 p.m. on Sunday, August 2

July 2009 was the busiest month in 36-year history of the EJMT, when 1,225,605 vehicles went through. It was the first time the monthly total exceeded 1.2 million vehicles, with daily traffic averaging 39,536 vehicles.

Additional 2009 EJMT traffic data:

Month           2008                2009                  Difference

January       1,006,889      1,069,155         62,266
February         958,369          942,316        (16,053)
March           1,108,534      1,079,123         (29,411)
April                  816,240         800,818         (15,422)
May                   803,156          850,766          47,610
June                  952,930          998,310           45,380
July                1,123,184       1,225,605        102,421
YTD Total   6,769,302      6,966,093        196,791

For more stats on the Eisenhower-Johnson Memorial Tunnels, see CDOT’s page.