The speed with which stretches of three interstate highways in Pennsylvania backed up with traffic during a recent snow storm demonstrated how traffic volumes are lowering the flashpoint for gridlock. It may be time to consider active access controls â€“ like traffic lights and barriers â€“ on interstate highway ramps.
In the Pennsylvania situation, motorists and truckers were stranded for over 20 hours in backups that closed 200 miles of I-81, 78 and 80 for several days. The National Guard had to be called in to deliver emergency supplies. All of which suggests that access controls in response to breakdowns are becoming increasingly important as traffic grows along the interstates.
In Pennsylvania, it might well have been desirable to have had traffic lights at the on-ramps â€“ in the style of California freeways â€“ to keep motorists from driving into the backups. A problem, though, is that motorists at remote ramps might be tempted to take their chances and drive through the stoplights anyway.
The possibility, perhaps desirability, of installing access control barriers on interstate ramps arises. PRO Barrier Engineeringâ€™s soon-to-be-introduced LightFoot barrier suggests what might be possible. The LightFoot â€“ a lighter-weight version of our Arrestor anti-terrorism barrier â€“ would be out of sight until signaled to rise from the roadbed. Monitored via wireless video cameras, the barriers could be safely operated from a highway department control room. Or they could be deployed at the scene by local law enforcement personnel.
Traffic volumes will continue to grow. Protection against gridlock induced by accidents or weather is becoming an increasingly important public safety issue on the interstates â€“ as all those motorists stranded in Pennsylvania could attest.
Finally, we should note that there are other reasons for considering barriers on interstate ramps. A series of horrific wrong-way drunk-driving accidents on interstates out west prompted the state in which they occurred to contact us about installing barriers on exit ramps. The barriers would deploy automatically if they detected a wrong-way driver attempting to enter an interstate via an exit lane. Work with that state is ongoing.