A Broad-Based Survey of Winter Roadway Maintenance Stakeholders in 25 States.
The use of video cameras and video displays on winter maintenance vehicles can help with operational decisions and enhance situational awareness for operators. The most common applications for snow plows are monitoring the rear of the vehicle, the wing plow, or the spreader. These areas are not visible from the driver’s position in the cab and cameras allow drivers to operate equipment more safely and effectively. In addition to supporting snow plows, cameras with video data feeds can be used to support traveler information systems and agency operations management.
The objective of this study was to understand the value of these systems to agencies, identify issues with their installation or use, and make recommendations. For this purpose, a comprehensive survey of winter roadway maintenance was conducted. The survey included a set of questions regarding the number and type of camera systems deployed, the system use, and installation or operational issues encountered. Twenty-nine (29) responses were received from agencies in 25 different states. Follow-up interviews were conducted in 2019 with three winter maintenance agencies and two manufacturers. Agency interviews included Minnesota DOT (MnDOT) due to its large-scale deployment with more than 200 plow trucks outfitted with camera systems. The second agency interviewed was the South Dakota DOT (SD DOT) due to reported maintenance and durability issues. The third agency included in the follow-up interviews was the City of Farmington Hills in Michigan due to its highest reported costs and reported installation issues. Both the survey and the follow-up interviews amounted to a good source of information for valuable lessons learned for other agencies.
- Include camera washer system and heated lenses on winter maintenance vehicles to avoid image quality degradation from dirt or snow accumulation. According to this study, the most commonly reported operational issue was degraded video quality due to dirt and moisture accumulating on the camera. This was most often observed on spreader, rear-view and wing plow cameras.
- Ensure proper display of camera feeds inside the vehicles. Results from this study confirmed that the in-vehicle displays should be able to show a minimum of four camera feeds simultaneously, along with integrated one rear-view and up to three equipment monitoring cameras. Cameras are recommended to be carefully positioned so they do not block driver sights and have adjustable brightness to avoid distracting reflections on windshields. Additionally, it is not necessary to integrate the video from forward-facing cameras into in-vehicle displays.
- Consider opting out of live video transmission especially in areas with poor transmission quality. Many cellular networks do not provide the performance needed to consistently deliver good quality video, particularly outside urban areas. Transfer recorded videos using Wi-Fi or USB once the vehicle has returned to the maintenance yard is recommended, if obtaining video feeds is desired but live video is not necessary.
- Use Power-Over-Ethernet (POE) cameras on vehicles when possible, to simplify wiring, installation, and operation. PoE allows for ease of camera communication troubleshooting. Ethernet-capable in-cab displays should be deployed in order to avoid the use of a separate video decoder.
- Purchase system components separately to save money. Cameras are often sold as packages with washer systems. Research showed that low-cost cameras can be used with washer systems, even if they are not initially packaged with them.
- Be sure to avoid cameras locked in on single software for video handling. When deploying a camera system, choosing a camera that does not create a “lock-in” condition where only one software solution can be used to view and manage video, is critical for practical functionality of the system.