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3 <br />Phase 2: <br />The car was then driven through a Styrofoam cutout representing an Attenuator, and the height <br />of the contact was determined to be 20 inches, by reviewing the digital image. Theta the car was <br />driven over the Vee at 65 mph and through another Attenuator placed 30 feet beyond the Vee. <br />The steering wheel was maintained in the straight -ahead position using a Ight touch. There was <br />no input required to maintain directional control of the car. The tire and rim was not damaged. <br />Review of the high-speed images did not show any vaulting occurred., The contact point of the <br />car with the Attenuator was determined to be 21 inches, after crossing the Vee, as demonstrated <br />by viewing the digital image. Although the test requirements specify that the contact heights <br />remain unchanged by passing over the Vee, it is apparent that the one -inch difference creates no <br />adverse reaction by this car. <br />Travel Test 2 -- Vaultina end -treatment <br />Approaching the end of the separator, at a zero degree angle and at 65 mph, the left front tire was <br />allowed to ride up onto and along the separator for a distance of 2 meters. The steering wheel <br />required only light contact and no correction was required. The car traveled the entire 100 feet <br />length of the separator and the driver removed his hands from the steering wheel for the last half <br />of the length. The tire and rim was not damaged. No vaulting occurred. <br />Travel Test 3 — Returning to the proper lane <br />100 feet of separators were installed in a straight line. The car approached, at 65 mph, along the <br />right side of the separator. The angle of approach was 2° as determined by review of a still photo <br />taken from the video showing the tire marks on the lane separator. Light steering pressure was <br />applied to the left, and the left front tine was allowed to climb over the separator. The tire <br />remained in contact with the separator during the entire event. The driver's subjective comment <br />concerning the effort required to cross the separator while maintaining control of the vehicle was <br />that some effort was required but that it was well within the normal range andtherewas never a <br />concern about maintaining control of this car. <br />Findings <br />The results of the testing showed that there was no tendency for the curb to cause the driver to <br />loose control of the vehicle, nor was there any movement of the curb sections that could lead to <br />separation. Therefore, the devices described above and shown in the enclosed drawings for <br />reference are acceptable for use on the NHS under the range of conditions tested, when proposed <br />by a State. <br />Please note the following standard provisions, which apply to FHWA letters of acceptance: <br />Our acceptance is limited to the crasbworthiness characteristics of the devices and <br />does not cover their structural features, nor conformity with the MUTCD. <br />Any changes that may adversely influence the crashworthiness of the device will <br />require a new acceptance letter. <br />