The explanation for this from our engineer is a bit technical, but here goes....As with any severely skewed bridge (45 degrees) with multiple short spans (5 spans varying from 50-60 ft) you will feel it in your vehicle as you move across the bridge from span to span. Especially in this case when the bridge width is 74 feet. The camber is greatest at the center of each beam. Since it is skewed at 45 degrees, the beams along centerline are at max camber when the fascia beams are on bearing (at a pier or abutment). This causes the rolling nature that you are referring to. The bridge is designed for a uniform deck thickness of 9 inches. Increasing the deck thickness to increase rideability could overload the beams.

I hope this information is helpful. If you would like to discuss this further or for information on other road-related concerns, please contact us directly for faster responses at geninfo@rcmcweb.org. Thank you.