Bob Ortblad discusses safety issues with the proposed grade of the I-5 Bridge replacement project
Editor’s note: Opinions expressed in this letter to the editor are those of the author alone and do not reflect the editorial position of ClarkCountyToday.com
If the Interstate Bridge Replacement Program’s (IBR) extremely steep bridge is built, a semi-truck will fly off the bridge and crash onto downtown Vancouver.
Bridge decks freeze before roadways because the air cools both the top and bottom surfaces. During winter months supercooled liquid droplets in fog will freeze instantly on the North-facing bridge deck forming dangerous black ice. With more warming sunshine the South slope will be ice-free.
A trucker driving north on I-5 will be lulled into the safety of dry roads and an ice-free South slope. The truck will slow to 45 mph climbing the +4 percent ice-free South slope. At the bridge crest, as the grade flattens the truck will gear up to 55 mph and then accelerate to 65 mph on the down-hill slope.
Two-hundred yards past the bridge crest the truck will hit black ice on the country’s steepest Interstate Highway bridge grade of -4 percent. Braking is useless on black ice and seconds later the truck will need to make a slight right turn. A 40-ton semi-truck cannot turn on black ice. At 65 mph it will crash through the bridge rail, falling 90 feet onto downtown Vancouver.
This unnecessary deadly design is criminal negligence. The IBR continues to ignore a safer weather-protected immersed tunnel alternative that will protect Vancouver from a falling semi truck, noise, and freeway blight.
Bob Ortblad MSCE, MBA
Seattle
