In Ames, Iowa, a survey of area residents indicated that 78 percent preferred an automated horn warning system that reduce the area impacted by excessive noise from 171 acres to less than 6 acres.
Date Posted

Evaluation of an Automated Horn Warning System at Three Highway-Railroad Grade Crossings in Ames, Iowa

Summary Information

This report summarizes the impacts of the installation of an automated horn system to warn motorists and pedestrians at three highway-rail grade crossings in Ames, Iowa (population 48,000). Flashing lights and gate arms existed at the intersections to warn motorists of an oncoming train, however locomotive engineers were required to sound the train’s horn to provide an audible warning at the crossing. Approximately 60 trains cross the intersections during a typical 24-hour period, which lead to noise complaints from nearby residents.

The new system, installed in September 1998, eliminates this need by sounding to two smaller horns located at the roadside and aligned in the direction of the roadway approaches to the grade crossing. Track signal circuitry, which also triggers the lights and gate arms, activates the roadside horns and a strobe light along the railroad which notifies the locomotive engineers that the automated system in operating. Engineers only need to sound their horns if the system is inoperable, or if they feel that a dangerous situation exists at the crossing.

The evaluation described in this report examined the changes in noise levels in the area before and after installation of the automated horn system, and the opinions of residents, motorists, and locomotive engineers regarding the system. Horn volume readings, in decibels (dBA) were taken in a grid pattern surrounding the intersections.


A mail-in resident survey taken two months before and two months after implementation determined that area residents were very satisfied with the system. 77 percent of residents indicated that the train horns had a "negative" or "very negative" impact on their quality of life before the automated system began operation. After implementation, 82 percent of residents responded that the automated horn was "no problem." Approximately 1000 total surveys were distributed, with 550 returned.

The project also surveyed motorist before and after implementation. 105 motorists responded before the system was implemented and 51 answered one month after the system became operational. Results indicated that 75 percent of motorists were aware that the system had been implemented, while 78 percent stated that they preferred the automated horns. The authors note that a significant number of the drivers surveyed are likely to be area residents, though the survey did not measure this.

Finally, this project surveyed the locomotive engineers seven months after the automated horns began operation. 92 percent of engineers indicated that the overall safety at the crossings was "about the same" or "safer" after the system was installed.
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