I have some problems with RD's realizing that it is important to do the measuring on a weekend. They want to complete it during the week, so they can have their weekends to themselves. I request that they also be out there, on a bike or with the officers. Any distance I measure over a 5k in downtown Orlando is done with police escort, even on weekends. I have completed most of my maps before I go out so that I only need to put the details into it after the measurement, and the officers and Race Directors all get a copy. I show them where the coning will go on a course and explain if I need to go against the traffic. They also know when I may be stopping to take notes for a key point.
I found that even with police escort, sometimes drivers don't care. Measuring a half marathon in Lakeland, Florida, a driver passed the officer, the two of us measuring, and the 3 course directors that were with us on bikes. The officer flagged the driver down and gave her a scolding. He would have given a ticket, but he didn't want to hold us up any longer than necessary. This happened at 7 am and we were getting close to being done.
My best experience with police escort was with one on a motorcycle. He could maneuver like us, and rush ahead to block off intersections. Also, his lights didn't blind us while we were trying to hold to SPR. His footprint was small, so if he was in front, I could still keep my eye on the tangents ahead.
I believe we've lost the interest of good measurers, because of the dangers out on the roads. I seldom look forward to the actual measurement, and I try to do as much prep work, to minimize my time out on the road.