There will be numerous roads closed in/around Cambridge, 4am - 4pm on Sunday 5th March, for the 2017 Cambridge Half Marathon. I don't currently see any closures in Waze, no reports from Elgin, nothing even on roadworks.org for this.
I won't have chance to collate the permalinks, and I couldn't action any closures anyway; perhaps a local editor could?

Sources: Event Website but more useful Road closures pdf Page 3 has all the details: road closures, exact road segments, direction, and times of closure; page 7 has an overview map of the route.

Many thanks