Harsh events increase by 1750% during one 2-week bridge closure
Las Vegas, NV (October 16, 2024) – Geotab ITS, A two-week closure in June of the highly-traveled Memphis-Arkansas bridge connecting the states of Arkansas and Tennessee resulted in an 1750% increase in harsh driving events such as harsh braking and fast accelerations. A Geotab ITS study on commercial freight data on 5 key U.S. bridges reveals that closures, whether short or long term, can have a significant impact on traffic congestion, increased risk of harsh events, and disruptions to the movement of goods beyond the region.
Geotab ITS provided a snapshot into what can be expected with a longer term replacement project and 2026 planned closure of the Memphis-Arkansas Bridge.
- The closure of the Memphis-Arkansas Bridge for two weeks in June 2024 led to increased traffic volume and travel times on the Hernando de Soto Bridge, with a 70.8% increase in travel time into TN and a 13.9% increase into AR during peak hours.
- The other key state bridge, the Hernando de Soto Bridge (which already handles 63% of all trips between the states) saw an increase of 61% in trip counts and total vehicle counts rose by 23%.
- Total harsh event counts peaked at 3 p.m., with 74 total harsh events recorded during the hour for vehicles traveling into Tennessee. This represents a 1,750% increase in harsh events observed on the Hernando de Soto Bridge during the closure compared to when the Memphis-Arkansas Bridge was open.
- Heavier traffic congestion along the Hernando de Soto Bridge could result in disruptions to commercial vehicle movement into Texas, Oklahoma, Ohio, Georgia, Louisiana, Indiana, and Missouri.
A map showing origin and destination insights for long-haul commercial vehicles. Green hexagonal areas indicate the journey stop locations of vehicles that crossed the bridge heading from Tennessee into Arkansas while en route to their destinations. Orange hexagonal areas indicate the journey stop locations of vehicles that crossed the bridge from Arkansas to Tennessee.
“Bridges are critical to communities whether they connect cities, states or large regional hubs and definitely need to be cared for, maintained and replaced. Using our commercial vehicle freight data, we conducted analyses of five important bridges across North America to demonstrate the potential effects of a significant disruption on the surrounding roads, driver safety, and regional economies,” said Geotab’s Nate Veeh, Associate Vice-President, Intelligent Transportation Systems (ITS). “These bridges had a lot to tell us including how far-reaching the impacts of a potential bridge shutdown could be on more distant locations’ supply chains.”
In its bridge analysis report, Geotab ITS studied the widespread effects of potential closures to show organizations how they can form better transportation plans with real world data. The study focused on five major U.S. bridges in and across California, New York, Tennessee, Michigan and Maryland and included the impact of closures, severe weather, and traffic patterns so that communities can prepare for replacement projects in advance.
Key Report Take-aways:
The Vincent Thomas Bridge – California
- The upcoming construction on the Vincent Thomas Bridge will likely cause delays for vehicles directly headed to and from the Port of L.A., but the farther-reaching impacts to the rest of the region need to be examined. Throughway traffic that uses this bridge as an important primary highway within this high-congestion area will be affected, resulting in commuter delays and likely supply chain setbacks.
- Multi Purpose Vehicles (MPV), which represents around 30% of the vehicle type breakdown, and heavy duty trucks (HDT), which represents around 28% of the vehicle type breakdown, will likely be the most impacted by the bridge closures. Those vehicles represent 27% local, 23% regional, and 18% traffic by vocation.
George Washington Bridge – Between New Jersey and New York
- The George Washington Bridge spans New Jersey and New York and is often referred to as the busiest bridge in the world. It is a two-way suspension bridge with 14 vehicle lanes, and it handles nearly 59% of all trips between New York and New Jersey. It is predominantly used by long haul and regional vehicles, with traffic peaking at 5-6am into NY and 12-1pm into NJ.
- Our analysis revealed a notable correlation between severe weather events and the bridge’s traffic patterns. The sharp increase in “danger probability” (a measure of generally how dangerous a route is in terms of collision probability) during a winter storm underscores the heightened risk of accidents under such conditions.
Ambassador Bridge – Between Detroit, Michigan and Windsor, Ontario
- As one of the primary routes for vehicles entering the U.S. or Canada, the Ambassador Bridge connects Detroit and Windsor and serves as an essential roadway for both passenger and commercial vehicle movement. In 2022, the bridge was home to over 260,000 commercial vehicle trips, with 60% of those trips being taken by heavy-duty, long-haul vehicles.
- During a six-day protest that shut down the bridge in 2022, closure impacts were likely felt in cities such as Montreal, Toronto, Columbus and Chicago
- Based on our origin and destination analysis, impacts extended as far south as Nashville, Cincinnati and Charleston. Drivers who were forced to take alternate routes experienced increased drive times and heavier arterial road congestion.
Francis Scott Key Bridge – Baltimore, Maryland
- Prior to its collapse in March of 2024, our data indicates that the bridge experienced over 4.2 million CMV trips across it, and more than 510,000 CMV vehicles annually.
- The aftermath of the collapse and subsequent recovery efforts resulted in the following predictable delays:
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- Traffic rerouting through the Baltimore Harbor Tunnel resulted in average drive time increases to 24%, while vehicles taking the Fort McHenry saw drive times rise to 15%.
- By our estimation, roughly 53% of previous trips across the FSK bridge redirected through the Fort McHenry Tunnel, approximately 10% traveled through the Baltimore Harbor Tunnel, and about 32% used either the Beltway or Baltimore City routes.
- Approximately 5% of previous FSK trips stopped going through the Baltimore area altogether.
“Our data and data insights from our bridge analyses helped us assess the key aspects of a transportation network’s integrity: infrastructure resiliency, roadway safety and transportation efficiency. Each of the bridges we studied provided us with unique viewpoints ranging from how extra traffic could impact alternate routes reasonably handle, how motorist safety is impacted through changing driver behaviors such as harsh acceleration and harsh braking and, the impact of movement of goods and services en route to their destinations and how far out closures could extend to. All of this data insight can be very helpful in anticipating and planning for bridge construction and making better transportation decisions that focus on safety, resilience and efficiency, “ concluded Nate.
Geotab ITS’ unique position in analyzing bridge traffic patterns
At Geotab ITS, we help governments develop smarter resiliency plans.
Geotab ITS’s strong reputation and vast data resources uniquely position us to analyze the impact of these bridges. With 80 billion daily data points from over four million vehicles, we are a leader in transportation insights. Data-driven bridge resiliency plans help minimize disruptions to daily commutes.
Our data insights provide valuable context, such as vehicle classes and vocations, enabling cities and states to create plans that support last-mile and long-haul deliveries and prevent bridge disruptions from impacting supply chains. Efficient transit drives economic prosperity, and understanding the commercial ramifications of potential bridge disruptions helps regions enhance their preparedness.