Full statement from VDOT on MMMBT barriers

The safety of the traveling public is VDOT's utmost priority. The concrete barriers at the I-664 Monitor-Merrimac Memorial Bridge-Tunnel (MMMBT) are designed and constructed in accordance with stringent safety standards to effectively manage and mitigate potential risks. These standards, established by national transportation authorities, consider various factors, including vehicle dynamics, traffic patterns, and environmental conditions.


It's important to note that incidents like the recent SUV crash, where a vehicle flips over the barriers, are extremely rare and often involve a combination of unique and severe circumstances. In fact, while the MMMBT averages about 75,000 vehicles per day, in the past five years, this is the only recorded incident of a vehicle going into the water from the bridge structure. (A second incident involved a vehicle from the roadway on the shore prior to the bridge, driving off the road, through a fence, and stopping in the water between the two bridge trestles.) The barriers continuously work as they are designed to prevent vehicles from going through, which we routinely experience in crashes at these facilities but don't get the same attention as the rarer occurrences that have occurred like yesterday's incident or at other facilities. The guardrails, bridge railings, and other roadside barriers at the MMMBT are installed in accordance with federal and VDOT design and construction standards, policy, and specifications that are current at the time of construction.


While increasing the height of the barriers might seem like a straightforward solution, it requires careful consideration of several factors:

1. Structural Integrity and Design Standards: Higher barriers necessitate significant structural modifications to ensure they do not adversely affect the bridge's overall stability and performance. Concrete barriers are reinforced with steel to enhance their strength and durability, but higher barriers would also add more weight to the bridge structures than the barriers they were originally designed for. Such changes would require comprehensive engineering studies and substantial financial investments.
2. Increased Impact on Vehicle Occupants: As noted by experts, higher barriers are also stiffer, which means that collisions can result in more severe impacts to vehicle occupants. While the higher barriers may reduce the rare occurrence of a vehicle going over them into the water, the everyday impacts from these barriers designed to redirect the majority of the traffic that hits them could increase in severity.
3. Cost and Feasibility: Implementing higher barriers across an extensive structure like the I-664 Monitor-Merrimac Memorial Bridge-Tunnel involves considerable resources, costs, and time. It would also cause significant disruptions to traffic during construction.

We continuously review and assess our infrastructure to enhance safety measures. While the current barriers meet safety requirements, we are committed to investigating any incidents thoroughly and implementing improvements where feasible. In the meantime, we want to take this opportunity to remind all drivers of the importance to adhere to safe driving practices, remain vigilant, and exercise caution to remain safe no matter whether the roadway is on land or over the water.