The selection of roadway safety equipment is not to be made based just on product availability and initial cost. Crash cushions are engineered to control the impact of vehicles on fixed hazards, barriers, gore areas, and other potentially hazardous areas in the vicinity.
Prior to ordering crash cushion attenuators, transportation practitioners should consider site considerations, traffic characteristics, proven performance, installation considerations, maintenance considerations, and standards considerations.
Begin With a Detailed Site Assessment
Each roadway site is unique. Prior to choosing a crash cushion, review the hazard that is being protected, roadway geometry, shoulder width, median configuration, traffic direction, clearance available, and surrounding infrastructure.
A thorough evaluation is used to determine if the equipment to be used will meet the safety needs of the site and for the purpose.
Understand the Expected Impact Conditions
Speed of traffic and vehicle attributes are key elements of crash cushion selection. Roadway operators, and especially transportation professionals, should take into consideration the speed at which the roadway is operated and the types of vehicles that typically use the roadway.
The impact force or forces that can be created by passenger cars and heavy vehicles may differ, and the chosen system should match the situation that it has been designed for.
When considering the use of crash cushion attenuators, consult manufacturer documents for applications and limitations that have been tested.
Verify Testing and Applicable Standards
The crash cushions need to comply with standards that are appropriate for the roadway for which they are used. Before identifying a product, verify its testing certifications, approved configurations, installation requirements, and applicable transportation agency criteria.
The evaluation and under what conditions the system was evaluated should be well documented. This information is critical for public projects, highway work areas, and areas where approval is required by the agency.
Consider Installation and Site Compatibility
A crash cushion is only as effective when it is used properly. Prior to ordering equipment, ensure that the required footprint, foundation or anchoring arrangement, transition details, terminal configuration, and clearance requirements are met.
Additional constraints might be introduced due to the temporary work zones, as the roadway space may vary depending on traffic pattern changes. While a technical system might be suitable, it may not be feasible to be installed at a specific site.
Plan for Inspection and Maintenance
Crash protection doesn’t end when installation is complete. Transportation agencies and contractors should have an understanding of the system inspection, maintenance, and repair requirements during its service life.
Equipment can be impacted over time by traffic, weather, corrosion, debris, and minor impacts. An easy-to-maintain system will minimize downtime and enable crews to restore protection more quickly after impact.
Evaluate the Full Cost of Ownership
The lowest purchase price isn’t necessarily the most economical choice. When choosing which cushion attenuator to install on your road, look at the installation expenses, parts and equipment required, maintenance, inspection requirements, lifespan, and technical support.
A more dependable system with lower upfront cost that has easier maintenance requirements and more parts availability might be found to be more beneficial in the long run.