GPS, Rt. 49 and king pins

We have a GPS in the RV that is made for RVers.  It is made for/by Rand McNally and offers some very nice features.  It will locate Walmarts that allow over night parking, or find gas stations that are truck friendly so our vehicle will fit.  We entered all our RV dimensions such as length, height, weight, how much propane we hold etc.  We even put in our total length with the Jeep attached.  The GPS is then supposed to keep us off any roads that would be hazardous with our particular vehicle.  There was one instance where it was giving us bad directions but we were made aware of the low clearance by the campground host and were easily able to avoid a problem.

In early October were coming out of Reno, NV. headed to a campground near Yosemite NP and the GPS directed us to take I-80 west then head south on Rt. 49.  We looked at a map and saw that 49 was going to cut some miles from taking I-80 west to 99 south then cut back east on 120.  We followed the GPS.

We turned on to 49 and about 100 yards after we were already committed (by this I mean we could not turn around)  we see a sign that says "30 foot king pin not advised".  While towing we are 56 feet long.  We did not know what a king pin was but we were concerned about the 30 foot part.  But there was no place to turn around or even pull over to disconnect and drive separately.  So we had to keep moving until we could get off or turn around.

This road was narrow, very windy with lots of hairpin turns and steep grades.  Some places offered no guard rail.  We were only able to drive at about 10 to 15 mph due to the turns and narrowness of the road.  And  the road was full of pot holes.  We drove for over an hour with both of us white knuckled with elevated heart rates and blood pressure.  Finally, we found a spot where we could get on a better road and head to route 99.  From there the trip was very nice.  What a day.

We have since learned that a king pin is where the pulling vehicle and the trailer attach.  So on a semi truck the king pin is where the trailer meets the rig.  So trucks with trailers can very in length.  We now avoid any road we can with a king pin warning.  Lesson learned!