Traffic Engineering and Operations Office

FDOT conducted a detailed statewide study of WWD crashes in Florida focusing on analyzing trends and contributing factors associated with WWD incidents on limited access facilities which also proposed several countermeasures for deployment. [Link]

FDOT conducted a driving simulator study of the effectiveness of countermeasures to prevent wrong-way crashes. The research findings showed the problematic interchanges would likely benefit from an increase in the number and diversity of countermeasures to prevent wrong-way crashes. [Link]

FDOT worked with Center for Urban Transportation Research (CUTR) of University of South Florida (USF) and evaluated a wide range of dynamic WWD countermeasures and determined their effectiveness based on several parameters. The countermeasures included:

1. Static signing and pavement marking (S&PM) standards
2. Red Rectangular Rapid Flashing Beacons (Red-RRFBs)
3. Red flush-mount Internally Illuminated Raised Pavement Markers (IIRPMs)
4. LED Highlighted “WRONG WAY” signs
5. Detection-triggered blank-out signs that flash “WRONG WAY”
6. Delineators along off-ramps
7. Wigwag flashing beacons
   

 

The study findings showed detection triggered Red-RRFB and LED Highlighted “WRONG WAY” signs with alert sending capability are two of the most effective countermeasures. [Link]

FDOT conducted a study with CUTR of USF to detect wrong-way vehicles using video detection method applicable for both on mainlines and off-ramps and send the detection alerts to a TMC/RTMC. [Link]

Another research conducted by FDOT focused on addressing the factors that were considered to affect the occurrence of WWD incidents: impaired drivers, drivers aged 65 years and older, and tourists. Findings from this study provide guidance to proactively deploy WWD countermeasures at all the off-ramps in Florida. [Link]

Why spikes should not be used for stopping wrong-way drivers?

While using spike strips on off-ramps may seem like a simple solution to stop wrong-way drivers by flattening tires, it may not always work as intended. The spike strips may also produce undesired consequences to drivers traveling in the correct direction. Below are some potential reasons why spikes should not be used at freeway off-ramps:

• Spike strips are designed for very low-speed locations. They are most commonly used in parking lots where the average speed is about 5 miles per hour. However, on the off-ramps, the traffic volumes are significantly higher than those in parking lots. Further, the average speed is also significantly high - ranging from 25 to 40 miles per hour. Lastly, there is no commercially available spike strip system that has been designed for permanent installation on roadways with speeds greater than 5 mph.
• Spikes may not deflate tires of wrong-way vehicles quickly enough to prevent vehicles from entering the highway. If a wrong-way vehicle reaches the freeway mainline with defective tires and continues to drive the wrong-way, it may still pose a threat to motorists traveling in the correct direction.
• Law enforcement and emergency responders sometimes use off-ramps to enter the mainline to respond to an incident more quickly. Having spikes on off-ramps may cause unwanted consequences to emergency responders and law enforcement officers.
• Right-way drivers may perceive spike strips in the pavement ahead as a hazard and suddenly apply their brakes, creating a dangerous situation.
• Permanently installed spikes that are broken or torn may cause damage to tires of the traffic traveling in the correct direction. Moreover, spike strips can be dangerous to motorcycles and small cars traveling in the correct direction.
• Dirt, debris, and other substances may build up in the devices and cause malfunctions.
• All traffic control devices installed on highways must comply with the Manual of Uniform Traffic Control Devices (MUTCD). Due to the risk of damaging vehicles and harming occupants traveling in the correct direction, spike strips devices are not MUTCD-compliant.
• Texas Department of Transportation provides reasons against spike strip concept. According to TxDOT, Spike strips have been considered by the industry, but they can pose significant safety and maintenance challenges. 
  • http://www.transguide.dot.state.tx.us/sat/wwd/content/EngineeringAnalysisSpikeStrips.pdf

Other states are also not considering installing spikes on their off-ramps for the above-mentioned reasons. Some news links are provided below. 

Ohio: 10 reasons why spike strips aren’t used to stop wrong-way drivers

Arizona: Will spike strips stop wrong-way drivers? ADOT responds to suggestions

Pennsylvania: Why Spikes Aren’t The Answer to Stopping Wrong-Way Drivers