I am going to comment here as an untrained victim and not consult my engineer friends. Most victims and the general public will have to rely on their own inner armchair engineer to comment on suggested regulations. We rely on NHTSA engineers that we pay to guide us on upcoming regulations technical options. Unfortunately, NHTSA is presenting only the cheap two vertical strut support mildly energy absorbing guard that corporations prefer. The general public needs to be informed we have more options and what some of the pros and cons are with each approach. We need realistic cost estimates that include cheap imported parts and not just price inflated American suppliers.
Why not a two tiered guard regulation. Provide safety conscience companies a gold standard they can meet and insurance companies can then give preferred pricing structure for the decreased risks. We know fully energy absorbing guard designs like those from MUARC and the Impact Project can perform to 50 mph and provide increased offset crash protection, we know extending guards out from the trailer increases the speed they can provide effective protection for. Pros and cons for a gold standard?
We know that with modern cars they can absorb enough crash energy through crush that 40 mph stiff brick wall guards become possible. You remove all energy absorbing requirements from the guard and build a super strong guard that is essentially a brick wall. We rely on the cars safety systems to absorb enough crash energy to survive a crash into a brick wall at 40 mph. What are the pros and cons of this approach which uses the guard to prevent PCI Passenger Compartment Intrusion and only uses the cars safety systems to provide all of the energy absorption? CMVSS No. 223 permits an option that a rear impact guard does not have to meet energy absorption requirements if it is able to resist 700,000 N of force using the distributed load application device without deflecting more than 125 mm. This would seem to allow a brick wall guard exemption but it is unknown if such guards would be built.
We know that adding an angled extra strut to the outside end of the guard improves offset crash performance of the guard. This might make the guard too stiff for full impact and 50 % offset crashes as NHTSA implies. We know from crash tests at MUARC these extra struts are very effective and would be no problem with a brick wall design. You could also design these struts as plastic rod pistons to absorb energy and not affect the stiffness for full and 50 % offset crashes. The design is cheap and simple and with new aluminum and high strength plastic formulations could be very light and still strong. You need a metal tube and a metal rod to go into the tube and form a piston. You place a printed or purchased plastic rod inside the tube to absorb the crash energy through crush. The plastic expands to fill the tube as the guard is pushed forward and as it crushes eventually it can expand and crush no more and it stops the guard moving forward any more, much like your standard oil filled piston. Pros and cons and variations, please explain NHTSA engineers.
Explain pros and cons of other types of guard designs such as Impact Project Pliers Guard that catches a car with cables that force the guard to pinch the car as it proceeds forward much like pliers. Crash test cars and trucks at real world highway speeds so we can have a real model in our heads to make these important decisions. It is not the job of IIHS to crash test trailers and trucks and their guards. It is your job NHTSA and through crash testing and public computer modeling you can engineer upgrade kits for current guards, companies can add engineered outer angled struts to improve older guard performance. They can improve the design and performance of new guards to increase sales as they go for the improved safety rating that comes from better crash performance. Design super guards and save lives by licensing them to the public domain.
We could require much more energy absorption in our approved guard designs and force the use of energy absorbing designs like those at MUARC and The Impact Project. Energy absorption: 50kJ minimum is recommended by research and crash testing of guards at MUARC in Australia. These designs make high-speed guards possible. The low speed 30 to 35 mph Canadian Standard guards are not the only option as NHTSA seems to suggest. We have the 40 mph brick wall option and also the near 50 mph energy absorbing guards options that might be better choices as most real world crashes exceed 35 mph.
The corporate guard that generates corporate political donations should not be the only option presented to the public. Tell the whole story good or bad. In a democracy, we should have the right as a general public to make an informed decision. We are not engineers, but the decision is ours, educate us as you are paid to do! These proposed regulations simply grant government approval of 93 % of the guards already on American roadways. They do not substantially increase safety for the next twenty years, the average life of these regulations. We will be changing to energy efficient lighter and lower vehicles and will need to examine crash effects of battery packs and hydrogen tanks. NHTSA gives an average guard height in America of 18 inches but claims guard heights above the road exceeding 22 inches will impact roadways? They refuse to give credit to lower guard heights ability to increase safety. This is not an Vision Zero regulation to increase safety and should be refuted on that basis alone. We demand an Vision Zero safety regulation process for all American safety regulations. This regulation as proposed will adversely affect victims lawsuits and protect guillotine killer guards from legal challenges and just reparations of the harm they inflict.