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A Robson Forensic highway engineer was retained to investigate a fatal incident in which a vehicle lost control on a highway exit ramp and crashed into a tree. The investigation was performed to determine if dangerous roadway conditions were a cause of the crash.

Excerpts from Report

Download the entire redacted report in the “Details” section of this page.

1. INTRODUCTION

This single-vehicle-run-off-the-road crash occurred 29 January 2003 at about 1:00 p.m. in Watchung Boro, Somerset County, New Jersey. The crash involved a 2002 Dodge 3500 passenger van driven by Conover Simms, with passengers Michael Osborn, Martin P. Tuttle, Eric G. Benson and Paul Clohosey.

Clohosey died and Simms, Osborne, Benson and Tuttle were injured as a result of the crash.

This investigation was performed to determine if dangerous roadway conditions were a cause of the crash.

3. DESCRIPTION OF THE CRASH & SITE CONDITIONS

Police Report:

Accident Scene:

This accident occurred on I-78 WB (Exit 41) Mile Post 42.4 in Watchung Boro, Somerset County. The conditions at or near the time of the accident were snowy, approximately 31 degrees Fahrenheit. The surface of the roadway was wet. The roadway, painted lines, and traffic signs were in good condition. The posted speed limit is 65 M.P.H. The lanes at the scene were curved with a downhill grade.

At this location the interstate consists of a left and right shoulder, three travel lanes, and a deceleration lane. The left shoulder measures 3 feet and is bordered by a grass berm. The left, center and right lane as well as the right shoulder and deceleration lane all measure 12 feet. The right shoulder is also bordered by a grass berm.

Vehicle Description:

This accident involved Vehicle #1: A 2002 White Dodge Ram 3500 bearing NJ Reg (NNE86N) VIN# 2B5WB35Z42K115658

Accident Description:

Vehicle #1 was traveling WB on I-78 exiting the interstate at Exit 41 (MP 42.2). Once on the ramp driver #1 was traveling at an excessive rate of speed for the conditions and lost control. Vehicle #1 traveled off the WB side of the ramp entering the grass berm. Once in the berm vehicle #1 remained out of control traveling approximately 35 feet before striking a large tree and coming to a final rest.

Driver #1 stated: “I was going too fast when I got off the ramp. I lost control and hit the tree.”

Simms testified:

  • He was a part time driver for LTI Transport (CS 9).
  • He had driven this van before (CS 16).
  • The weather conditions worsened. Coming out of East Rutherford the roads were wet.
  • The weather changed from rainy bordering on freezing rain to some snow. (CS 47).
  • As he was exiting Route 78, the weather caused the steering not to respond. He went off the road into a bank of trees (CS 51, 52).
  • He had made this trip before and was familiar with where he was going. (CS 83).

Sporer is a police officer who witnessed elements of the crash from a position just beyond the end of the ramp. Sporer testified:

  • There was a light, wet snow (BS 12).
  • The road had wet slush on the surface (BS 12).
  • The speed of the van was 30 – 35 mph as it left the ramp (BS 14).
  • The van went straight off the ramp (BS 18).

Consistent with Sporer’s speed observation, Williams, et al, concluded that Simms struck the tree at about 33 mph. At my site inspection I located the stump of the struck tree at 36 feet from the edge line of the ramp.

I conclude that the conditions of this crash were as follows: it was snowing, the pavement was wet, Simms went off the outside of the ramp curve at a speed of about 35 mph, and the vehicle struck a tree about 35 feet from the ramp.

13. FINDINGS

Within the bounds of reasonable engineering certainty, and subject to change if additional information becomes available, it is my professional opinion that:

  1. The conditions of this crash were as follows: it was snowing, the pavement was wet, Simms went off the outside of the ramp curve at a speed of about 35 mph, and the vehicle struck a tree about 35 feet from the ramp.
  2. The right-hand curve was too sharp for Simms’ speed and the road conditions.
  3. There were no traffic control devices to warn Simms of the sharp ramp curve.
  4. The ramp curve is sharper than usual for a freeway exit. The sharp curve is a violation of an exiting driver’s expectancy and, in the absence of appropriate traffic control devices, made the roadway dangerous in a manner that caused this crash.
  5. The safe speed for the ramp is 20 mph.
  6. The ramp curve is too sharp according to both NJDOT and national criteria.
  7. The exit ramp curvature is substandard, and the curve cannot be recognized by approaching drivers. This should have caused NJDOT to recognize the sharp ramp curve as a problem location, one that offers a surprise to the driver.
  8. A means of mitigating the hazard of the sharp curve is by altering a driver’s expectancy through installation of appropriate traffic control devices. In this case, devices should be provided to show approaching motorists that there is a sharp curve ahead with a safe speed of 20 mph and the nature of that curve. These devices should include a curve warning sign and chevrons to mark the outside of the curve.
  9. Per NJDOT documents four Chevrons, and a series of yellow delineators at 25’ spacing, should have been present along the outside of the ramp curve; however, these devices were not present at the time of the crash.
  10. The missing delineators and Chevrons that were supposed to be in place along the outside of the curve was a critical lack of guidance to Simms that was directly related to the happening of the collision.
  11. For all but one of the 10 years prior to this crash there was at least one crash similar to the Simms crash. As should be expected, there have been a substantial number of collisions related to the sharply curved and unmarked exit ramp.
  12. Removal of trees to a distance beyond 50 feet from the ramp would have been reasonable and prudent.

Download the entire redacted report in the “Details” section of this page.

 

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