Wednesday, March 08, 2006

A Tale of Two Bridges

What a difference 65 years makes.

This is the Interstate Bridge, where I-5 crosses the Columbia River between Portland, Oregon and Vancouver, Washington. The East span is the original bridge, constructed in 1917. That makes it 89 years old. It was designed in the era of the Model T Ford, a 1200-lb car with a 22hp engine. The matching span to the west of it was actually built more than 40 years later, in 1958. This bridge is fairly narrow for cars and trucks, but carries 3 lanes of traffic in either direction. Unless they have to raise the lift span for water traffic, in which case everything comes to a screeching halt.

It's not so friendly for bicycles.

We get to contend with this - a very narrow sidewalk added as an afterthought. If the width wasn't bad enough, it can get pretty windy while over the river, with the wind threatening to blow you into the rail or into the bridge supports (this almost happened to Tomas a month ago). Also, there's a bit of a hill, where barges and shorter ships can pass under the bridge without having to wait for the lift span. When going down the other side, one can pick up a fair amount of speed. Imagine negotiating this sidewalk at speed, and seeing it narrow with metal signals, gates and electrical control boxes at the lift span (avoiding these is why I have no pictures of them)

Ok, fast forward 65 years after the first bridge was completed, to 1982. Here's the bicyclist's new friend - the Glenn Jackson Bridge. Ugly as sin, but it has this really cool bike lane down the middle of the bridge! Here, look:

Here's the ramp on the Vancouver side, running up from the bike path next to SR-14 to the bridge level. Is that not cool?

The Vancouver side is at about 200' elevation, the Portland side is about 40' elevation, and the entire bridge is over 2 miles long. On a good day (without a headwind) you can cruise down in at 30 miles an hour or more while cars whiz by on either side at 55-75 mph.

Again, very cool.

Here's what it looks like from up on the bridge. Cars everywhere, but the bikes (and the occasional pedestrian) protected by solid concrete and steel. I love riding it, unless I have a serious headwind like I did last Sunday when I took these pics. I never got above 15 mph. Still, it's a really cool bridge.

At the end, the bike lane dips down into a trench between the bridge halves again, and ends in a solid wall.


Well, Ok - they give you a chance to take a hard 90 left rather than tumble over the fence and down onto Airport Way.

And did I mention the view? There wasn't one last Sunday, which is probably why I almost forgot, but you can see the airport, all up and down the Columbia, and a beautiful unobstructed view of Mt. Hood.

Which of course is why I like this bridge.

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