According to NHTSA, American students are nearly eight times safer riding in a school bus than with their own parents and guardians in cars. The fatality rate for school buses is only 0.2 fatalities per 100 million vehicle miles traveled (VMT) compared to 1.5 fatalities per 100 million VMT for cars. This impressive safety record is a result of the Department of Transportation's requirements for compartmentalization on large school buses, and lap belts plus compartmentalization on small school buses.

The NHTSA report concluded that requiring lap belts on large, new school buses would appear to have little, if any, benefit in reducing serious-to-fatal injuries in severe frontal crashes. In rare circumstances, tests indicate that in some severe frontal crashes there may be increased risk of serious neck injuries and possibly abdominal injury among young passengers wearing lap belts. read the full report

However, in September of 1999 the NTSB issued a report on school bus crash-worthiness. The study found “compartmentalization” was ineffective during six typical school bus accidents. In every example the 222 seat failed to contain the passengers. Children were injured and killed as a result of both ejection and being tossed violently within the bus itself.

The Board concluded that:

Current compartmentalization is incomplete in that it does not protect school bus passengers during lateral impacts with vehicles of large mass and in rollovers, because in such accidents, passengers do not always remain completely within the seating compartment.

The Board went on to point out that passengers who were propelled from the “compartment” were the ones more likely to be injured during side impact and rollover collisions.

"Over 200,000 children have been injured since the inception of compartmentalization because of the failure of the compartment protect children in school bus accidents" said Dr. Arthur Yeager, co-founder of The Safety Lobby.

And yet, according to NEA (http://www.nea.org/esphome/issues/seatbelt.html) bus driver concerns fall on the side of no seat belts.

Bus Driver concerns:

• Students can and do use the heavy belt buckles as weapons, injuring other riders.
• It is next to impossible to make sure that all students keep their belts properly fastened, so that they are not injured by the belts in an accident.
• If a bus has to be evacuated in an emergency, such as a fire, panicked or disoriented students might be trapped by their belts.

What is the solution? How can the road safety industry keep children safe while riding the bus to and from school?

Most slip base posts seem to be derived from the AASHTO Roadside Design Guide criteria. The Austroads report AP-R200 "Frangible Sign Supports Part 2: State of the Art Review" Section 3: International Practice and Literature Review 3.1.1 AASHTO Roadside Design Guide states "The guide discusses location of signs to minimise the risk of the support being struck. The mechanism of failure is dependent to some extent on what height the vehicle strikes the support. For this reason the likely impact position may be affected when locating supports on slopes. Where possible the supports should be located on level terrain."

AP-R200 section 2.9 also reported discussions with representatives from each state. Responses included "Concern that if a sign is not struck at the normal height (eg flat approach) that the sign will not fail properly. This may be as a result of a vehicle striking a kerb, or travelling out of control down an embankment". There are two problems here. One is that hitting the sign high means uncertainty whether the slip base will function. The other problem is if the slip base does function and if the hinge point functions there is still a heavy steel post behind the sign. There is a chance of the steel post penetrating the windscreen and entering the cabin of the vehicle. This would apply particularly for high vehicles like trucks. Anywhere that a car is likely to become airborne is a location that slip base posts should not be used.

AP-R200 section 2.9 reported another concern; "Frangible signs at intersections are difficult to cater for, with the possibility of the sign being struck from almost any direction". This is a problem with slip base posts. They have been designed to be hit from the front or back, but not from the side. Truly frangible supports will absorb the energy of the impact no matter where they are hit.

Austroads publication AP-T47 06 Revision of Guide to Engineering Practice - Part 8 - Traffic Control Devices 5.2.3 Large Supports when describing slip base posts warns "However they are designed for impact up to a limited angle and may not perform as intended if struck from the side."

AP-T47 06 5.5 Installation and maintenance issues for frangible supports states, "The following aspects are critical to the successful behaviour of a frangible sign support:

• Base bolts must be installed and maintained at the tension specified on drawings or in specifications
• The frangible mechanism must be installed at the correct height above the ground surface. If it is too low the surrounding surface may impede the correct operation of the slip base, and if it is too high an impacting vehicle will snag on that part of the base that remains in place
• The ground level around the base plate must be compacted and finished so that it remains at the correct level relative to the slip base, debris will not build up around the base, and the soil will not erode from around the base
• Hinges should be installed strictly in accordance with drawings and should not be modified (e.g. by welding) for any purpose as part of maintenance operations.

AP-T47 06 5.2.2 Small Supports states, "... it is important that the spacing between posts is such that an errant vehicle is likely to only collide with one of the posts. Opinion varies on the spacing, a value in the range 1.5m to 2.4m being adopted."

AP-T47 06 5.6 Frangible post selection guidelines states, "In selecting post numbers and sizes the:

• Smallest possible number of posts should be used
• Distance between posts should not be less than 1.6 metres to avoid the risk of an errant car simultaneously striking more than one post

I submit to you that although steel slip base posts are infinitely safer than rigid posts, they do have limitations in their applications. I believe the following limitations should be applied to the use of slip base posts immediately.

1. Slip base posts be banned from filled batters of 1:3 or greater or where the base plate will be more than 400mm below the road level. This is a Danish regulation, Norwegian Road Authority specifies batters steeper than 1:4. The Norwegian specification should be adopted by January 1, 2012

2. Slip base posts be banned from gore areas as the GE2-3 exit signs are (a) likely to be hit, (b) likely to be hit at an angle greater than the design parameter of the slip base post, (c) the post is likely to finish up on a roadway, and (d) a vehicle is likely to hit more than one post simultaneously as the signs are 1.8m wide giving a standard post spacing of 1.08m (1.8 x 0.6).

3. Height of stubs above ground of existing installations should be checked and any rectification works to be completed within 12 months.

4. Torque settings of bolts on existing installations should be checked every 3 months for at least one year, until it is evident that the torque is not changing.

5. Installers are to be liable for checking and maintaining torque settings for 5 years from installation. This is to be introduced after an Approved Sign Installer program is initiated. The price of this checking is to be included in the initial installation price. Records of torque settings to be presented to the Approved Installer Program administrator.

6. Slip base posts to be banned where it is likely that a vehicle will hit the sign from an angle other than the design angle. This includes within 60m of an intersection.

7. Slip base posts to be banned where the is kerbing.

Points 1 to 6 can be avoided by using an approved energy absorbent post. A post may be considered energy absorbent if it meets the requirements of NCHRP 350 or EN 12767 and has a failure mechanism which does not rely on a slip base. It must function when struck from any direction. Full crash test reports to either standard must be supplied to Queensland Main Roads. The full scale crash test must use a vehicle as specified in the standard. Computer simulations will not be accepted unless the largest and smallest posts in a "family" of posts have been successfully full scale crash tested. The structural requirements must be satisfied by showing compliance with AS1170.2 2002 - Structural Design Actions - Wind Actions and a relevant Australian Standard. This compliance must be from an independent Australian certified Structural Engineer. Foundation sizes are the responsibility of the manufacturer / supplier. It is suggested that these are designed an independent Australian certified Structural Engineer.

Also the following restriction should be placed on all posts.

Unless protected by a barrier which is there for another purpose, no posts may be installed with less than 1.5m between the posts. Note: Minimum centre to centre of posts is 1.5m plus one post diameter. Hitting 2 x 50NB posts is the same as hitting 1 x 100NB post.

It was approved at the UN General Assembly that a road safety conference will be held in 2009 in Russia. The goal of the meeting is purportedly to gather together high-ranking ministers of transport and health from most of the U.N.'s member states who will discuss road safety issues and should hopefully spur real change.

The IRF applauds and fully supports the UN resolution and the upcoming conference. It is much needed and long over due. As government officials and policy makers come together to combat this epidemic, IRF encourages all to remember that road safety isn't just about driver bahvior - wearing seat belts, driving slower, not driving intoxicated.

Road safety needs a three-pronged approach - the driver, the vechicle and the road.

Although a sweeping change in driver behavior would do much to curb the current carnage on the road, it is not an all inclusive solution. Vehicles need to be safer and the roads certainly should plan for accidents. For no matter how safe a driver or secure the vehicle, humans will always make mistakes and vehicles can malfunction. And the road should be designed, built, and equipped in order to forgive that mistake, and mediate vehicle failure.

An all-inclusive approach to road safety should include the transfer of technology and the proper training to implement such technologies, including such topics as, but not limited to:

• Roadside Safety & Median Application
• Proper Vertical & Horizontal Signage – Delineation and Illumination* Work Zone Safety
• Intersection and Roundabout Safety
• Low Cost Safety Improvements
• Pedestrian Safety
• Safety Technology Concepts
• Traffic Calming
• Enforcement
• Safety Audits
• Collection and Use of Statistics

What other problem areas can we improve in order to build better, safer roads?

The Road Safety Working Group is open to all IRF members who have an interest in road safety. The Road Safety Working Group meets once a year and holds two or three conference calls during any twelve month period. During these meetings and conference calls, ideas, opinions, and information are exchanged in order to capture all views of any given topic. This all-inclusive approach ensures that IRF-Washington policy statements on road safety will be a sound, diverse representation of the worldwide road building community.

Once the IRF-Washington Road Safety Working Group finalizes a policy statement, the proposed policy statements are presented to the IRF Council on Road Safety (the consortium of Road Safety Working Groups from Brussels, Geneva and Washington) for their endorsement and support. During the meeting of the IRF Council on Road Safety, all working group members have the opportunity to speak on behalf of the proposed policy statement. Once the statement (or white paper) is approved by the Council, IRF presents the approved policy during a ministerial meeting to key government decision makers from around the world. Currently, IRF has more than 70 ministries and road directorate members. Road Safety Working Group members may be invited to meet with the ministers to discuss the policy statement.

If the IRF Council on Road Safety does not endorse a position statement from one of the Road Safety Working Groups, the Road Safety Working Group is allowed to publicize the position statement with the clear designation that the position statement is only supported by the single Program Center and not by the IRF as a whole.

Upcoming position statements include, but are not limited to:

• The need for on-going road safety training as it relates to roadside safety, intersection/roundabout safety, vulnerable user safety, work zone safety, driver education, enforcement techniques and road safety audit
• Motorcycle use continues to grow around the world and motorcycle accidents and fatalities continue to rise at an alarming number. How can road authorities modify their road design, education and enforcement procedures to reduce these fatalities?
• Congestion in municipal areas is worse than ever causing safety, productivity, and environmental concerns. What innovative concepts should be considered to alleviate congestion in municipalities?
• Poles located close to the road can be extremely dangerous. The use of breakaway devices and other technologies to make these rigid roadside hazards less dangerous by allowing the vehicles to pass through should be endorsed and encouraged. What can be done to promote the expanded use of these safety features?

Members of the IRF-Washington Road Safety Working Group will be able to effect real change in the world. This is a great opportunity to have an attentive audience of key governmental decision makers around the world who will hear the voice of the industry and listen to your counsel.

Join the IRF-Washington Road Safety Working Group

Road authorities in countries that do not have updated or adequate roadside safety feature specifications should use either the European EN 1317 or the American NCHRP 350 criteria or both of them when developing roadside safety hardware performance specifications. The development of specifications outside NCHRP 350 and EN1317 would be both time consuming and expensive and would not produce better safety hardware at a cheaper price. The EN1317 and the NCHRP 350 criteria have proved to be very effective. Allowing products that meet either criterion will give the local road authorities more product options thereby reducing project costs.

During their meeting on January 14, 2008, the following proposal was approved unanimously by the AFB 20(2) Roadside Safety Design Subcommittee on International Research Activities for those countries currently not required to use NCHRP 350 or EN 1317 criteria to create performance specifications for their roadside safety features.

"The AFB20(2) Roadside Safety Design Subcommittee on International Research Activities recommends that road authorities in all countries should only specify roadside safety hardware, (i.e. longitudinal safety barriers, crash cushions, terminals and transitions) that has met either NCHRP 350 or EN 1317 criteria (or their updates.)"

The IRF (Washington and Brussels) support and endorse this statement and encourage every road authority around the world to implement this policy. Spending money wisely to use current, proven state of the art technology, products and concepts will help to make the roads safer and better.

Full scale crash testing, required by the new proposed NCHRP 350 update in the United States, has shown that some multiple post sign panel designs currently in use are not capable of resisting the forces exerted when one of the support posts is impacted. The result is the inability of the impacted post fuse/hinge plates to activate, which could cause the failure of all of the remaining frangible bases. It is critical for safety that a multiple post sign should remain standing and be supported by the posts not impacted. The post fuse/hinge plates are critical components in the resultant change in velocity of the vehicle and passengers.

Research is needed to study the structural characteristics of ground mounted sign panels that are currently installed on multiple posts, This research should include a survey of sign panel designs currently in use and subsequent modeling of each design. Simulation crash testing should be performed with both the small car and pickup truck. Simulation should be verified by full scale crash testing. The final report would result in minimum sign panel design criterion for use on multiple post ground mounted signs with either breakaway posts or base assemblies with fuse/hinge plates.

How do we get this research funded and started?

Mike Stenko has over 25 years in the industry and has been with Transpo for over 16 years. He is a member of TRB, ACI, ASCE, Chairman of ACI Comm. on Polymers Concrete. Sub-Comm. Chair of AASHTO/AGC/ARTBA Taskforce 13 Subcommittee on highway signs and luminaries.

That issue is not only a problem in most of the Latin American countries. It is also a problem in the USA and many countries of the "first world".

There are AASTHO´s standards regarding the width of shoulders (depending on the number of lanes in each direction), etc. So why don’t the geometric design engineers follow those standards?

There are many cases in which the problem of widening a road in terms of lanes would sacrifice the width of the shoulders. I believe it is more important to have a road with right and left shoulders keeping the width in each case depending on the number of lanes in each direction.

I have seen same problem in toll roads (access to the city of Buenos Aires) and in a freeway from La Guardia Airport to the City of N.Y.

What is more important – a wider road or a safer road?

As an example: two young boys were killed in a traffic accident on one of the toll roads in Argentina a few months ago. Their car experienced some mechanical failures and they had to stop the car on the left lane of the highway because there was no shoulder. Before the driver could alert the following drivers, a car crashed into the back of the stopped vehicle.

Who is responsible? The highway department that authorized the design? The professional engineer who did the design? The concessionaire, who without caring about safety, built the road without a left shoulder? Or the economical reasons to increase the amount of tolls and to keep the road at an acceptable traffic level?

Same thing applies to many roads in the USA and around the world.

Are we going to accept such things?

Traditionally motorcyclist safety has not been taken seriously into consideration when developing longitudinal barrier testing criteria. Europe recently announced plans to include motorcycle testing into the EN 1317-2 longitudinal barrier testing matrix. The Unites States recognizes the need to do something and is currently evaluating options.

A variety of products have been developed to protect motorcyclists who impact longitudinal barriers. Most of these products, many of which come from Europe, are designed to shield the posts of the steel barrier systems. This is logical since motorcycle riders often are thrown from their motorcycles and are sliding along the ground when they hit the barriers.

I have heard some experts say that they believe that a motorcyclist impacting a concrete barrier, or a steel barrier or a cable barrier system will die. It is just a question of “how dead will you be, 100% or 140% or 160%?” However, the real debate comes from the motorcyclists complaining specifically about the cable barrier systems. They refer to these cable barriers as “cheese cutters.” They cite an accident in October of 2007 in New Zealand where a motorcyclist impacted a cable barrier and the motorcyclist was severed from the waist down. The motorcyclists want the cable barrier banned in New Zealand. This opinion has been voiced in other countries around the world.

Some road experts believe the cable barrier actually is safer for motorcyclists when it is impacted. They explain that the cable barrier steel posts are more likely to fracture when impacted. They also claim the cable barrier will be placed further away from the road because of the working width of the cable barrier.

Both sides of this issue need to be explored and this issue needs to be resolved. The question is simple; are cable barrier systems more dangerous for motorcyclists than steel barriers or cable barriers, are they safer, or are they the same? Your comments are welcomed on this site.

The issue of motorcycle safety and longitudinal barriers will be the focus topic at the AFB 20 (2) Roadside Safety International Research Subcommittee meeting at TRB in Washington DC on Monday January 14 from 3:45 PM to 5:30 PM. This meeting will be held in the Balcony D Room of the Marriott Wardman Hotel. All are welcome to join this meeting to listen to a variety of experts define the problem and then suggest a variety of solutions. Your input to the cable barrier-motorcycle safety issue on this IRF Road Safety Matters blog is strongly encouraged to get as many opinions as possible voices on this topic.

Allowing either the US or European criterion to be used will provide economic benefit for the local road authority through increased competition. Since both testing criteria require basically the same light car test (820 kg vehicle – plus dummy weight in NCHRP 350 and 900 kg vehicle including dummy weight in EN 1317-2, 100km/h and 20 degree impact angle) the limiting factors will be the impact severity of the capacity test and the anticipate number of high center of gravity vehicles. A longitudinal barrier that meets EN 1317-2 or NCHRP 350 should be allowed to be used provided the capacity test impact severity of the barrier is higher than the capacity test impact severity of the specified longitudinal barrier. The impact severities of the different levels of barriers in EN 1317-2 and NCHRP 350 are shown in Chart 1 below.

Chart 1: Comparison of Impact Severity Levels

For example, if a road authority decides the most appropriate longitudinal barrier for a road should be the EN 1317-2 “N-2” classification, then any barrier that has an impact severity greater than 81 kilojoules should be allowed as well. This means NCHRP 350 Test Levels 3, 4, 5 or 6 as well as EN 1317-2 Test Levels N-2, L-1, L-2, L-3, L-4a or L-4b also could be used on this project.

If accepted at the upcoming Annual Meeting in January in Washington DC, The TRB AFB20(2) Roadside Safety Subcommittee on International Research would strongly recommend that all road agencies require that longitudinal barriers meet the minimum performance standards as outlined in EN 1317-2 OR in NCHRP 350. A safety factor should be included when determining the severity level to be specified. If a significant number of trucks are anticipated on the road, a higher center of gravity barrier should be specified. Furthermore, the TRB AFB20(2) Roadside Safety Subcommittee on International Research would recommend that impact severity levels be used to specify the minimum capacity for a longitudinal barrier and that any barrier with a higher impact severity level be allowed to be bid on the project regardless if the longitudinal barrier has been tested to EN 1317-2 or NCHRP 350.