COLORADO I-70: Congo tolling in the Rockies - getting skiers to pay their way

December 10, 1997

COLORADO I-70: Congo tolling in the Rockies - getting skiers to pay their way

Originally published in issue 22 of Tollroads Newsletter, which came out in Dec 1997.


Subjects:congestion pricing CP




It seems quite likely the Colorado Dept of Transp (CDOT) will next year ask for proposals for staged widening I-70 west of Denver with tolls, and innovatory management of traffic lanes involving congestion-pricing and high occupancy incentives. By end-97 consultant CH2MHill is expected to produce a recommended option from among various rail, air and highway enhancements — the latter including 6-laning, HOV, congestion priced tolls, and dedicated bus lanes.

Under study is 200km of I-70 Denver-Glenwood Springs, the main highway west out of Denver from the Great Plains up into the Rockies to the ski resorts around Vail and Aspen, the casinos of the old mining towns like Black Hawk and Central City as well as spectacular fishing, hiking and sightseeing. It is also the most direct truck route between Chicago and Los Angeles. CH2MHill project leader Don Ulrich says at weekends in both summer and winter there are already major problems with many miles of backed up traffic: “Last July 4, I went up there to look and it was a 30 mile traffic jam. It was quite ugly, and the general scenario of serious backups is repeated nearly every weekend during the summer months. And it is beginning to become a problem many winter weekends too."

Average traffic numbers don’t seem large by normal motorway standards — 9m vehs/yr, daily average of 24k vehs/day. But this is no normal mwy. For one thing it has major holiday peaks in both winter and summer with up to 44k vehs/day.

Also it is North America’s steepest long-steep interstate mwy. It rises from 5300ft elevation (1600m) in the plains around Denver to 11,000ft (3400m) at the Eisenhower Tunnel through the Continental Divide of the Rockies and has prolonged grades of 6% or more for many miles. Ulrich says 1300 vehs/lane/hr is approx the maximum throughput in this terrain (60% of the capacity of a less mountain-challenged roadway.) And he notes that special care is needed to provide reasonable safety in these steep high altitude conditions where blizzards can blow in 6 months of the year and icy conditions can be especially treacherous.

3 to 4% growth/yr: Traffic has been growing 3 to 4% annually and businesses in the Rockies are concerned that their future is in jeopardy if transport improvements are not made. The ski fields of Vail, Aspen, Eagle etc could lose out to rivals in Utah. At the same time the Rockies attract ferocious environmentalist opposition to construction proposals, both because of the direct impact of the enlarged facility and because many residents favor no-growth policies of keeping out extra visitors to preserve their quality of life. It took much expense, ingenuity and persistence on the part of CDOT and FHWA to complete I-70 to 2x2-lane mwy standard through the Glenwood Canyon just a few years ago.

The natural grandeur of this region, most agree, justifies extraordinary measures to blend any transport improvements into the splendid landscape. But fierce arguments will rage over which alternative represents the best solution.

From a simple engineering standpoint the best solution might be to add a third 2-lane roadway at least to Vail, making the central 2-laner reversible. Already it is common to reduce the contra-peak direction to one-lane for several hours to run 3-lanes in the peak direction in order to clear congested traffic. The 2x2-lane Eisenhower Tunnel (3.4km) will almost certainly have to have a third tube at some point — if only because it is too difficult and disruptive of traffic to widen the existing tubes. The third tube might be built to 12m or so to accomodate 2-lanes+ shoulder or 3-lanes, allowing one of the existing 2-lane tubes to be reverse flowed.

But Ulrich says a third separate roadway outside the tunnel section has been ruled out because of its “greater footprint.” His team is working on a cross-section that would widen the existing roads to 2x3-lanes, with the inside left lanes reserved for buses or HOV/HOT in the most likely version.

Options: the various build options are:

(1) New rail transit Denver-Vail and Vial-Eagle/Garfield/Pitkin and enhancement of air service — capital cost $5b to $7b, ongoing large subsidies (bus service needed until 2005 completion date for rail)

(2) Expand highway to 2x3 lanes, new bus service, air enhancement — capital cost $2.5b to $3b, ongoing subsidies for bus and air

(3) Expand highway to 2x3 lanes with third lanes to be HOV, with air enhancement bus subsidies — capital cost $2.5b to $3b, subsidies ongoing

(4) Rail Denver-Vail and compromise highway improvement consisting of third laning 43km C-470 to US-40 turnoff (before Georgetown) and steep grade Dillon-Silverthorn section, air service enhancement — capital cost $5.5b to $7.5b

(5) Travel Demand and System Management of the highway with congestion price tolling, flexible/reversible lanes, extra climbing lanes and some new frontage roads to keep local traffic off mainline, rebuilds of 16 interchanges — at a cost between $470m and $770m

Rail enthusiasts are quite numerous at the public meetings being held on the options and some have claimed the engineers are biased against rail and have inflated its costs. Ulrich denies this saying rail is so expensive because if the grade is to be kept to rail’s normal max 4% then some tens of km of tunnel is needed in the 200km corridor, though the team is pursuing data on the operations of rail and other fixed guideway systems at steeper grades.

Cutting the tunnel work to present fixed guideway at less of a cost disadvantage to the highway option will produce more fixed guideway right of way or structure that has to be fitted into the canyons and valleys that comprise most of the route.

The capacity-enhancing scheme with least environmental impact would seem to be some mix of (3) and (5). Passenger rail is problematic almost anywhere these days but it seems especially far-fetched and extravagent in these mountains. But if they can't get rail the anti-highway crowd may end up opposing virtually all the capacity-increase options.

Congestion pricing tolls will enable the existing to capacity to be used much better by shifting demand for the road out of the peak times. Businesses and communities in the Rockies will almost certainly want any tolls to be accompanied by some capacity enhancement for fear of losing business, and there will also be safety arguments for capacity enhancement. This is dangerous territory for traffic jams!

Tolls are already established in Colorado as the fairest way to pay for Denver’s eastern beltway E-470, and HOT lanes are being discussed on I-25 north. Tolls were used in the mid-1950s to build the Denver-Boulder Turnpike, now de-tolled US-36. The traffic crisis on the Denver-Glenwood Springs segment of I-70 is caused principally by high-income vacationers and recreationists, so the equity argument for financing improvements with tolls seems strong. The project team is also very interested in the potential of variable toll pricing to help them manage demand on I-70 and reduce peak overloads. (Contacts Sam Atencio CDOT, Don Ulrich CH2MHill 303 771 0952x5248, Tom Schilling 303 534 5409)

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