What should drivers be cautious of when they encounter signs or markings that say "NEV USE ONLY" or "NEV ROUTE"?

• Speed up to pass these vehicles quickly
• Ignore the signs and continue driving as usual
• Watch out for slow-moving vehicles with a maximum speed of 25 mph
  Explanation:

  "Watch out for slow-moving vehicles in the road when you see these signs or markings "NEV USE ONLY", "NEV ROUTE.""
• Use the road freely, as these signs are not relevant to regular traffic