Because it's 1.5 miles from the bridge to the River Park neighborhood, there isn't a direct bike route from there to the bridge, and even if there were one it would be a three-mile trip one-way to Cal Expo, compared with less than a mile going straight across. Remember, too that they mentioned pedestrian and bike access; while three miles might not be too much for bike riders, expecting someone to walk that far is too much, especially in the summer.