Agree with Desert Captain. Just visited daughter in SD 2 weeks ago the highway only reduces to 1 lane but the speed is still 60. It has been that way for close to a year now. Never have had a issue.
2014 Arctic Fox 30U
2001 Silverado 2500 HD, 4WD
8.1 Vortec / 4.10 gears / ATS Stage 2 Allison Transmission with Co-Pilot
Tekonsha Prodigy P2 Brake Controller
Reece Class 5 Hitch with 1700lb bars