Measuring Sign Retroreflectivity for Nighttime Inspections
Updated: Oct 7
Signs for Improvement
In 2023, the University of Wisconsin at Madison determined it needed to update its roadway sign inventory on campus. Student safety, especially at night, is paramount.
Cloudpoint Geospatial was subcontracted to update its road sign inventory, including capturing the geographic location of all signs on roadways and in parking lots. Cloudpoint offers a complete sign inventory system using SignOps®, a mobile-friendly application for tracking and managing sign assets, so it was a perfect fit.
Cloudpoint's technical staff conducted the initial geospatial collection of the signs using an iPad loaded with the SignOps® application. The inventory involved capturing several sign attributes, the XYZ location, and, in some cases, a photo of the sign in place.
Once the inventory was complete, the project moved to retroreflectivity inspections of all assets to help the Client target poor-quality signs for replacement. Federal Highway Administration (FHWA) regulations require all roadway signs to meet a minimum level of nighttime retroreflectivity. To meet this requirement, all signs should be measured for retroreflectivity using one of two methods:
Nighttime visual inspection
Measured sign retroreflectivity
Cloudpoint chose the first method, using a two-person crew: a driver and a passenger/inspector.
Lights on for Safety
Before conducting the roadway sign surveys, the team calibrated the vehicle headlights to ensure they were properly aimed and functioning. The inspection team carried out the headlight aiming procedures after sunset, as defined in the Federal methods manual for maintaining sign retroreflectivity. Once the headlights were calibrated, the team determined the inspection routes and began inspections.
Early on, it was determined that to maintain a safe speed and route, the team would record the street signs using an iPad mounted in the vehicle. The recordings began with the inspector announcing the starting intersection to establish the starting point and direction of travel, providing the vehicle's orientation.
There’s a Signpost Up Ahead!
Next, as the vehicle moved down the roadway past the signs, the inspector called out the sign type and its reflectivity condition. Federal standards require noting sign reflectivity as “good, fair, or poor.” At the end of a street, when the driver reached an intersection, the inspector called out any required vehicle turns and provided the name and direction of the new street to create a complete record of the road and camera orientation.
The team inspected the entire network of campus road signs over two evenings. Vehicular and student traffic made navigation and collection challenging at times, but after driving a few roads, the team established a routine and the process went smoothly thereafter. At the end of each night, the team backed up all video recordings to cloud storage for the technical team back in the office.
Back-Office Data Verification and Edit
When the crew returned, they began updating the data in SignOps® by determining the starting point, starting the video, and updating the attributes for each. Because videos could be replayed, they verified and accounted for sign locations from the previous inventory work.
The campus sign inventory project was a good example of how Cloudpoint and SignOps® can efficiently and accurately collect sign assets for any campus or municipality. The resulting inventory will keep students, faculty, and residents safer around campus for years to come.
For more information about Cloudpoint Geospatial services or the SignOps® application, contact us at: https://cloudpointgeo.com/contact
