The Rhode Island Department of Transportation (RIDOT) today began posting data from its weigh-in-motion technology (WIM), part of a new monitoring system installed on the eastbound Washington Bridge. This precautionary tool provides RIDOT with real-time information on overweight trucks crossing the bridge.

In addition to the WIM system, RIDOT is in the process of installing structural health monitoring (SHM) technology on the bridge. This will utilize sensors in the bridge to inform RIDOT in real time how the bridge structure responds to overweight trucks, allowing the Department to determine any effects on the bridge by the passage of these vehicles.

"Safety is RIDOT's highest priority," RIDOT Director Peter Alviti, Jr. said. "As part of our comprehensive efforts for maintenance and inspection of the eastbound bridge, we installed this state-of-the-art system which will allow RIDOT to have its finger on the pulse of the bridge in real time, every day, around the clock."

The WIM technology alerts RIDOT when overweight trucks cross the eastbound bridge. While the weight limit for trucks on the bridge is 80,000 pounds, trucks weighing up to 96,000 pounds may cross the bridge if they have a permit to do so. In the event that a truck weighing 140,000 pounds or more crosses the bridge, RIDOT follows up with a visual inspection to ensure that the load did not affect the bridge.

Based on the data observed to date, the number of trucks weighing over 96,000 pounds represented only 0.05 percent of the combined 133,000 vehicles using the bridge in both directions each day. It is important to note that full inspections of the bridge are taking place more frequently—every six months—as another precaution.

The Department has set its oversized permit limit conservatively, in accordance with independent engineering evaluations, to assure the bridge will not be affected by the additional traffic in the current bypass configuration; trucks weighing less than 96,000 pounds are not considered a safety concern.

Data from the WIM system is posted on the Washington Bridge closure web page at www.washington-bridge.com and will be updated every Wednesday with the prior week's data.