Apologies if previous postings on this subject.
UPS has used a right-turn policy since 2004 and it works. UPS drivers are encouraged to take routes using only right-turns, as avoiding left-turns in downtown areas reduces long idle times in heavy oncoming traffic. If interested, see this Priceonomics article: http://priceonomics.com/why-ups-trucks-dont-turn-left/
Adding a right-turn 'rule' to BaseCamp, as a Route Preference option, would be appreciated.
Paul333_