Audio technology effective in driving salt routes

Jamie Banks
Communications Intern
City of Grand Junction, Colorado

In growing cities, salt routes can change all the time, and while existing employees have a difficult time with transitions, incoming employees can be even more at a loss. Cities then spend time and money training employees, updating route maps, and making changes that may be ultimately less than efficient. So a problem is posed to street maintenance personnel: "How can you make the salting process more efficient and versatile?"

The challenge was answered by public works employees in Grand Junction, Colorado, with the help of evolving audio technology. David Van Wagoner, streets systems maintenance supervisor, devised a process whereby streets personnel can put real-time, verbal route directions for all city snow routes on a single compact disc.

Crew leaders Scott Norton and Jason Brown ran the routes in empty salt trucks and used a mini tape recorder to record directions in real time, leaving the tape running during stoplights and other traffic interruptions. Van Wagoner then re-recorded the "voice over" instructions as .wav files in his personal recording studio, but found he couldn't fit the nearly 12 hours of route directions on one disc. After working with both .wav and .mp3 files unsuccessfully, Van Wagoner found that by recording the directions as .wma (windows media audio) tracks, he could fit over 12 hours of material, leaving room for real-time instructions, such as filling and emptying liquid mag. chloride trucks.

The versatile process allows Van Wagoner to splice the driving direction tracks with background music tracks according to the tastes of a particular driver. It also allows for changing street or route locations to keep up with growth or priority issues and works much the same way as the cut and paste operations in a word processor or spreadsheet program. With the discs, he no longer has to keep the same drivers on the same routes all the time, and when drivers complete their runs, they can help other drivers with their routes by simply switching to the numbered track that corresponds with the new route.

The City of Grand Junction is located in a high desert climate in western Colorado, but does receive snow and ice throughout the winter, and maintains a fleet of 11 vehicles for sanding and snowplowing.
While some crewmembers were enthusiastic about the idea, others felt less than convinced the process would work. After trying it out on willing crewmembers, Van Wagoner tested the idea on those whom he felt might "find" problems with the system, or be less technologically inclined than others. Not one of the returning employees had anything negative to say about the success of the process, and only a few experienced difficulty with the CD player (initially more complicated to operate because of the filing system it requires to catalog the street locations for the routes). No one had problems after troubleshooting instructions.

One crewmember returned from testing the system and said, "I can't believe how well this works. When I was coming to my next street the CD informed me of the street, what my application rate (single lane, double lane, etc.) and spread width should be, and where I would be going next. I was always one step ahead."

Van Wagoner found that while driving with headphones is illegal, drivers may wear a single earbud (about $20). (Laws vary in each state; check with your local law enforcement agencies to make sure.) With the bud, drivers can hear the directions and still hear traffic and their two-way radios.

"The goal was to have any driver be able to run any route, as efficiently as a person who ran the route exclusively before," Van Wagoner said, "and I think we're pretty close to that."

There are some challenges, however, to implementing such a program. While agencies involved in snow and ice removal may not have an employee who owns a recording studio, some minimal requirements are necessary. A computer with a sound card, a microphone that can plug in to the sound card, and an office or other place where the noise can be somewhat controlled is a good start. (An office divider or sound absorbing panel would also work well.) While the cost for .wma players is minimal (about $160 each), the software Van Wagoner used (including Sonic Foundry's Acid Pro 3.0 ($399), Vegas Video 2.0 ($479) and Sound Forge 4.5 ($399) could run up to $1,500. (Van Wagoner points out that other, less expensive sound editing software is available and would also do most of the processing needed for this type of project.)

There are also certain conditions built into the program, for example that route drivers have to run their routes at the same average speed as those who did the original dry runs. And while the cycles of stoplights and overall traffic timing is different at night than it is during the day, drivers can use the pause, fast forward and rewind features of the CD player to stay current with their locations. Grand Junction also has storms when three, five or eight truck routes are operating and have made CDs for each of these scenarios.

Another advantage of the program comes in knowing almost precisely where each salt truck is at a given moment. A route book accompanies each disc, and track numbers correspond to track times and locations, so the Snow Desk dispatcher knows where drivers are in case of an emergency or service request. Upon receiving such a request, the driver can pause the player, travel to the requested location and take care of the situation, then return to their original place in the route and continue where they left off. This flexibility also allows drivers to return for more material, stop and check their equipment or material status, or make a "pit stop" and be able to continue where they left off, no matter how much time has elapsed.

When all is said and done, this process has allowed the City of Grand Junction to be more effective not only in winter storms, but also when it comes to the constant challenge of growth and public expectations of safer and more consistent service.

For more information, contact Dave Van Wagoner at (970) 256-4111 or at