Reporting measures

Reporting measures are clearly defined to ensure raters measure the same elements in the same way. For example, the rating standard for hazardous debris is: any objects on the shoulder large enough to pose a safety threat, including animal carcasses. The reporting measure is the number of such objects. The way in which a rater would measure this would be to walk the segment and count and record the number of pieces of debris large enough to pose a safety threat.

A complete list of these measures with in-depth explanations can be found in the Ratings Manual.

Weights and measures

The ratings system uses weights and measures developed by highway operations workers to evaluate and describe the condition of our highway system. Such weights and measures reflect expert judgment on such questions as:

• At what point does a crack become a maintenance problem? 
• How do we know how bad the cracking is? 
• How important is cracking to the performance of the traveled way? 
• How important is the traveled way to the performance of the highway system?

Statistics

Compass uses statistical sampling as its method of data collection. Statistical sampling uses a sample of the overall population (here the population would be all segments of state highway in Wisconsin at the time of the data collection) to estimate some characteristics of that population. This is what polls are doing when they talk to 1,000 likely voters to get a sense of how the majority of all voters will vote on election day.

People choose to sample rather than inventory an entire population because it is less expensive and they can get close to the actual average for less time and effort. Because certain pavement data has already been gathered and inventoried for all segments of road, it makes sense to use that existing data in collaboration with sampling data for non-pavement features to provide an accurate overall picture.