Neha Patil (Editor)

Vista Ridge Tunnels

Updated on
Edit
Like
Comment
Share on FacebookTweet on TwitterShare on LinkedInShare on Reddit
Traffic
  
Automotive

Operating speed
  
50 mph (80 km/h)

Opened
  
1969–1970

No. of lanes
  
6, 3 in each bore

Route
  
US 26

Vista Ridge Tunnels

Address
  
US-26, Portland, OR 97201, USA

Similar
  
Washingt Park MAX Station, Vista Ridge Capital Partners, Broadway Bridge, Ross Island Bridge, KGW

For miranda the vista ridge tunnels


The Vista Ridge Tunnels are highway tunnels through the Tualatin Mountains ("West Hills") of Portland, Oregon, United States. Located in the Goose Hollow neighborhood, the tunnels pass through a hillside locally known as Vista Ridge which is a half mile (1 km) west of downtown Portland. Sunset Highway, also known as U.S. Route 26, is carried through the tunnels, three lanes in each direction. They are Oregon's busiest tunnels.

Contents

The eastbound tunnel is 1001.0 feet (305 m) in length; the westbound tunnel is 949 feet (289 m). Both have 41 ft (12.5 m) of horizontal and 15.58 ft (4.75 m) of vertical clearance. The eastbound tunnel was completed in 1969, the westbound a year later.

There is a six-percent grade through the tunnels. Most of the tunnels' lengths are straight, though they curve southward at the west ends 35°.

The tunnels were built with ventilation shafts which were never used. Instead, the shafts were later adapted for electrical wiring, so as to improve tunnel illumination without marring the tunnels' appearance with visible conduit.

To improve tunnel safety for motorists, and decrease the tunnel lighting requirements, the original tunnel entrance faces were sandblasted to remove white paint and repainted a less luminescent tan color to reduce the range of visual light adaptation required by drivers. At one time there were computer-based electronic light controls, but they were replaced by relatively simple photo detectors and relays for durability and simplicity. The night lighting level is enabled permanently and is supplemented by two or three levels of daytime lighting.

Except directly over the tunnels, the hillsides are steep and undeveloped forest, with some residential development along the top of the ridges. Landslides occasionally occur, but are usually minor and quickly cleared.

The tunnels have been closed to hazardous material transport since November 1, 1994. As a result, US 26 is closed to hazardous material transport between I-405 and Oregon Route 217.

The tunnels are located nearly at the bottom of a hill where the road gradient averages 6.5% over 2.25 mi (3.6 km). Close to the east portals is a 130-foot (40 m) tunnel underpass carrying SW 18th Avenue. Just outside the west portals is a 650-foot (200 m) tunnel under the lanes which carries eastbound Canyon Road from the exit ramp into Goose Hollow. The Robertson Tunnel for MAX Light Rail is underground approximately 800 feet (250 m) to the west.

Traffic volume

They are the busiest tunnels in Oregon, 12% busier than I-5's 6-lane Interstate Bridge, and 2% busier than I-205's 8+ lane Glenn L. Jackson Memorial Bridge. They carry about 25–35 percent more traffic than New York's Lincoln Tunnel which claims to be one of the busiest tunnels in the world.

References

Vista Ridge Tunnels Wikipedia


Similar Topics