Long Course vs. Measured Course - Probably doesn't belong in this thread (Difference between cal and course surface) however there's some good discussion to be had here. Let's talk about a course (accurately measured) with 2-way runner traffic. I think the Measurement Procedures Manual, Shortest Possible Route chapter provides sufficient guidance. I know it has for us.
If a race director proposes a course with 2 direction runner traffic, especially on a non straight section, we always inform him that that section will have to be coned to prevent runners running less than the measured distance. If the RD agrees, we measure a restricted route (one side, one way; the other side, the other way) and show and state the restrictions (location of cones) on the map. If the RD does not agree to cones, we measure the shortest, unrestricted route. In the second scenario, the RD has created a race where the runners (especially the lead runners) almost certainly will run longer than the measured distance.
This is a dilemma I don't think the RRTC or the measurer or Certifier can reasonably resolve without reams of regulations and, ultimately, lawyers. I feel that we (the measurer) has done due diligence by informing the RD that some runners may run longer and offering an alternative.
What are the consequences of measuring (accurately) the shortest unrestricted route, knowing that some runners will have to run longer than the stated distance? Any record set on the course would still be valid, assuming all other conditions for records are met. The course could still be successfully validated or verified. The only negative consequence is the possible lost opportunity of a record performance. This is clearly beyond the jurisdiction of the measurement community as the possibility of a record always exists and always can be lost. This of course doesn't consider runner complaints of long course or unfavorable opinions about the race. These are not the measurers' concern, especially after due diligence and accurate measurement.
By the way, I agree and always have that a course measured at 5K must be certified as 5K. In this case the "5K" is the "advertised distance" that I referred to. Sorry for any confusion on this point.
Another by the way; I believe it is far beyond the responsibility of the measurer or certifier to check every (or any) USATF certified course set up on race day. That is the job of the RD or the RRTC if the race is a USATF Championship.