Shoddy guardrail on Garden State Parkway nearly killed NJ Governor Corzine

The police report on the accident which seriously injured New Jersey Governor Jon Corzine on the Garden State Parkway (GSP) Thursday evening says that the guardrail end "penetrated the vehicle and struck both (the driver State Trooper) Rasinski and Governor Corzine."

Guardrail ends are supposed to be properly buffered and anchored down so they don't come loose and form the kind of potentially deadly spear described in the police report, suggesting that it was shoddy engineering of this safety system by the Parkway that nearly killed the governor of the state.

The Governor's vehicle was hit by a swerving pickup on the right front fender, a hit which by itself is unlikely to have caused injuries. That hit by the pickup caused the governor's vehicle to spin out of control and into the guardrail end just off the roadway pavement in the median. It was this vehicle-guardrail end impact that was the big crash which caused the traumatic injuries.

The guardrail in question is steel Thrie Beam rail, a wider variant of a W-beam section of steel rail that has been in extensive use for over fifty years.

Barriers are usually recommended in medians of less than 15m (50ft) to prevent errant vehicles crossing into the opposite traffic direction. Such 'crossovers' are usually the most deadly accidents.

However the barriers themselves cause a crash, and the ends of barriers potentially a very severe impact.

According to Insurance Institute for Highway Safety data in 2005 9,057 people were killed in the US in fixed object crashes of which tree hits accounted for half (4,573 deaths) the total. Utility poles killed 1,223 (14%), embankments 567 (6%) and guardrails 451 (5%).

Hits on guardrail killed more people than lighting and sign poles, bridge pier abutments, curbs, walls, fences, culverts and concrete objects.

The ends of guardrail or barrier are especially hazardous as Gov Corzine's condition illustrates. There are three quarters of a million ends of guardrails in the US and they generate 15,000 collisions, over 100 deaths and about 5,000 injuries each year for a total cost of $500m/yr - according to a Texas Transportation Institute (TTI) report.

Steel guardrail is one of the oldest barrier systems in use, also the crudest and cheapest.

Alternatives to the steel section guardrail include more solid concrete barrier on the hard end, and on the softer end various more forgiving tensioned cable systems. Most tollroads in the US use solid concrete barrier so the Garden State Parkway is somewhat unusual in its use of steel rail.

But whatever the kind of barrier special treatment of the ends is needed for safety.

There are a huge array of buffering and shock absorbing 'end treatments' for barriers.

Don Ivey an engineer at TTI writes that "in the last ten years the safety of guardrail end treatments has been vastly improved..."

Ivey says most of the early designs and testing were for vehicles hitting guardrail ends head-on, although many hits on guardrail ends are sideways hits - from out of control or spinning vehicles, just like Gov Corzine's crash. Sideswipe crashes of this kind can be especially dangerous since there is none of the front crumple zone of the engine compartment to absorb collision energy.

In 2002 FHWA endorsed Collision Performance Side Impact modification to guardrail end treatment ET2000 especially to attenuate sideways hits on guardrail ends. TTI's Don Ivey designed this in the early 1990s, filed a patent in 1996 and was granted the patent in 1998. see http://safety.fhwa.dot.gov/roadway_dept/road_hardware/barriers/pdf/cc81.pdf
 

BACKGROUND
Gov Corzine suffered life-threatening injuries in the crash Thursday night including trauma to his chest which broke 12 ribs and his collarbone and a severely broken and mangled upper left leg with a huge open wound. He lost half his blood before he could be stabilized.

He was sitting on the side of the vehicle where it hit the guardrail end.

The accident happened northbound near Mile Post 44 on the Garden State Parkway just a few miles north of the entry from Atlantic City. Corzine was in the front passenger seat of a Chevy SUV driven by a state trooper. Spokesmen say he may not have been wearing a seat belt. Also the vehicle's airbags did not deploy. It is unclear whether the vehicle had side airbags.

If the guardrail penetrated the vehicle the seatbelt and airbags might not have saved him from the spearing injury to his leg, but they may have prevented or mitigated the chest injuries.

Corzine was flown by a medical helicopter to a Camden hospital that specializes in trauma injuries. He is heavily sedated and on a breathing machine and doctors say is doing well. They say however he  faces risks from infection, and is likely to have many months of rehabilitation before he can walk again. TOLLROADSnews 2007-04-15