June 25, 2002

I.D. Number: P-3812
County: Northampton

Subject: Bi-annual Report # 2 and # 3
North Carolina Innovative Traffic Control Field Experiment of the EVA Signal System;
FHWA Project: Request VIII-53 (Expr.) North Carolina EVA RR-Xing Signal System

Mrs. Debra Chappell
Federal Highway Administration
Office of Railroad Development
400 Seventh Street, SW
HOTO-1, Room 3408
Washington, DC 20590

Dear Mrs. Chappell:

The North Carolina Department of Transportation’s evaluation of the EVA Signal System installed at the North Carolina test location has determined that the EVA detection system installed at the SR 1521 (Lovers Lane Road) location contains faults that could be a causal factor in a grade crossing collision.

The primary concern revolves around the back up detection system. The detection system was designed with a Primary detection system that uses a speed trap to calculate warning time and then a back up detection system that acts like an island circuit (if the train passes a backup probe, it activates the signals). If the primary system has recently been activated (within 3 minutes) then the system relies on detecting train movement from two backup probes located at 150 feet and 1540 feet on each approach. It was determined that a short consist (three locomotives) could be lost in the detection system between the two back up probes. The short consist activates the signals when they pass the back up probe at 1540 feet. The logic system would not see the locomotives pass the primary activation probes, as these are deactivated while in back up mode. The system would determine that the event was not train induced based on an internal timer for further activity and would deactivate the signals shortly after they were activated. The system next recognizes a train movement when the lead locomotive passes the back up probe located at 150 feet, which would provide approx. 3 seconds of warning time before the locomotive entered the crossing at track speed. This should only be possible for short consists, but we observed some instances where this occurred for long freight trains. In addition, we have observed video of some trains that were provided with 3 seconds of warning time with out any prior activation. After reviewing the log data and video, we determined that on occasion, the system activates in back up mode when it should be functioning in the primary mode.

Some other problems we have observed with the system include:

• Tail ringing when the system is in back up mode.

• Water entering the underground vault through the electrical conduit. We had to install a standard signal house after the system was installed in running.

• Incorrect calculation of train speeds on one of the speed traps which consistently provided conflicting train speed information. Sometimes the train speed was more than doubled with the second speed calculation.

• Malfunction of the Train Directional Advisor causing the TDA to cease operation.

• Malfunction of one of the animated cross buck displays causing the display to become stuck in one illumination phase.
  

Currently, the EVA System has been installed since September 28, 2001. At this point, we have determined that a driver behavior study assessing drivers’ response to the EVA Signal System would be faulty as the signals have been bagged for more than 9 months and are considered "old news" by the local residents that utilize this crossing. In consideration of this, we propose to revise the scope of this project.

Our current plan of action is to remove the strobe flashers and replace them with standard LED flashers. We will relocate the animated crossbucks above the flashers in accordance with MUTCD. EVA Signal Corporation has redesigned the detection system based on evaluation of the system to date. We plan to have EVA Signal Corp. replace the existing detection system with the new EVA 3000 detection system for evaluation. We will allow for two months of evaluation before the decision is made to replace the entire system with standard equipment or to remove the bags from the standard flashers and animated crossbucks.

Please contact me at (919) 733-5587 if you have any questions.

Yours very truly,
Jason L. Field, P.E.
Crossing Project Engineer

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