A heads up to all RVers using SR-55 through Cascade. DOT has reduced the axle weight for ALL vehicles on the north bridge to 9K/axle and will be further reducing it to 6K/axle this week. They are serious about this as the bridge is now considered unsafe for any heavier weight and they are going to start setting up temp scales on both sides of the bridge. They also plan to have flaggers on both sides to control traffic 24/7, as they say 2 max weight vehicles crossing in opposite direction could cause the bridge to collapse. These weights and restrictions apply to ALL vehicles, including RVs.There is an alternate around the bridge, Thunder Mountain Rd, but it is approx. 4 miles of dirt and holes, plus right now is closed because a commercial rig tried to use it and is stuck hard in a soft spot.They will start emergency construction of a new 5 lane bridge on 1 July, but the weight restriction will remain in effect for a couple years. Please check with IDOT before driving all the way up here and not be allowed to continue.

Are you talking about the bridge over the Payette River at the north end of town? We are trying to figure out where Thunder Mountain Road is and where it would come out at the other end.We have reservations at Cascade Lake State Park this summer, so I guess we will have to figure it out before that.

Yes, that is the bridge, the one everyone fishes from. Thunder Mountain Rd runs from just south of the airport to Warm Lake Rd, on the east side of town. Most RVs are within the weight allowed, with only the very large trailers and most Class A's excepted. However, there are several routes to the SP that you can take to bypass the bridge, if coming from the north. Coming from the south, the bridge is not a factor going to Cascade Lake SP.

This is the bridge on the North End of Cascade. Must be the one by the dam. Here's an article on it. Thanks Texan for the heads up. Note the weight limits in the article. Seems that the average RV'er will be alright. If not, you can go around through Weiser and New Meadows.

I as told by a DOT employee Friday, that they had a meeting this week and those numbers I posted were the new numbers and that the actions I spoke of were going to be instituted this coming week. I do know they are now inspecting the bridge daily for further failure.The bridge was originally scheduled for replacement 2 years from now and they changed the start to 1 July because of the degradation.

The load limits from the OP are in pounds, but the load limits in the linked article are in tons. If the limits are really in tons, most RVs under 45' diesel pushers can use the bridge.As indicated, the rules may change at any time so one should contact IDDT before trying to use the bridge.

Idaho SR-55 bridge warning | Good Sam Community

Haulinhazmat
Explorer
Apr 25, 2014
Had a driver in Casper, Wy who's Fuel gage showed empty so he put in $20.00 worth of fuel thinking he could make Denver. Yes I said twenty dollars, $ 20.00.
Thought I had seen it all but guess not.
DianneOK
Explorer
Apr 25, 2014
Let's hope the story doesn't end with some fool ignoring advise and taking out the bridge I need to cross to go south......
Haulinhazmat
Explorer
Apr 25, 2014
I spent over 30 years in the trucking business but thank you for the lesson on axle weights.
The question was about the weight limit on a bridge, is the limit 6 tons per axle, 9 tons per axle or
6 thousand lbs or 9 thousand lbs per axle. I'm waiting to see how the story ends
DRTDEVL
Explorer
Apr 24, 2014
Haulinhazmat wrote:
Correct me if I'm wrong but with a weight limit of 9 tons per axle a tractor trailer combo with 5 axles could
Weigh 90 thousand lbs and cross this bridge. A MH weighs about 50 thou. Could not cross . Right
Or wrong

Almost correct. The front axle on a semi-truck (as well as most class As) is limited to only 6 tons. Each tandem (pair) set is limited to 17 tons due to their proximity to each other (not their individual weight ratings). This gives 34+6, or 40 tons.

Now, a wiggle wagon (double trailer) would have 6(f), 17(d), 10(t), 10(cd), 10(t), or the ability to hit a max of 53T (reality would be still limited to 40T, as they would be hard-pressed to hit the max weights per axle).

the question I would have is if the 9T limit applied to tandems, or if 17T is still acceptable. Those with a tag on their MH would need to know this, as the tag counts in a tandem calculation.
The_Texan
Explorer
Apr 24, 2014
OK, I got back from an out of state trip yesterday and immediately called the local district IDOT employee who gave me the information and asked WHY the discrepancy between what he reported and what the DOT is reporting. Had to wait till this morning for the answer and I can believe what he said he was told this AM. ONE word, politics. The numbers he gave me were directly from the engineers that inspected the bridge and put in writing as the "safe" limits for the bridge, so my 16T RV will NOT cross that bridge under any conditions.

This is a resort area and it seems that if they loose bus service, supply services and visitors for 2 years, they think the area will dry up and blow away.

Now that I know the reason, all I will say, is believe who you want, but I put my faith in the engineers who went under the bridge and spent close to 3 weeks doing a comprehensive inspection. The state must also believe them, even though they will NOT follow their safety recommendations, as the state immediately changed the replacement date for the bridge, to commence immediately.
Haulinhazmat
Explorer
Apr 23, 2014
Correct me if I'm wrong but with a weight limit of 9 tons per axle a tractor trailer combo with 5 axles could
Weigh 90 thousand lbs and cross this bridge. A MH weighs about 50 thou. Could not cross . Right
Or wrong
ReneeG
Explorer
Apr 22, 2014
DianneOK wrote:
Reneeg.....consider taking the West Mountain road around the lake....it will add miles, many, but at least you can save your trip.....

It could be by that time, Thunder Mountain road will be in better shape. We are in spring thaw right now and many roads are iffy.....

Thanks Dianne. When I mentioned this to my husband, he said West Mountain Road is a good one. We took it winter before last in our Jeep and it's wide and smooth for a FS road.
AH64ID
Explorer
Apr 22, 2014
RCMAN46 wrote:
" then compare the IDOT sign on the north side of Horseshoe Bend"

Could someone in the area of subject bridge post some pictures of the weight limit signs!

If a bridge had a 6000lb limit I do not understand why the bridge would not just be closed to all traffic.

I am hoping that the Texan will do just that. I am guessing he is in Cascade as he was at a meeting on the subject, but am not sure if he is venturing south this week or not.

I will be driving thru Horseshoe Bend on Friday and will take a photo if one isn't posted by then.

I agree, 6K lbs/axle to me seems to unsafe to even remain open.
RCMAN46
Explorer
Apr 22, 2014
" then compare the IDOT sign on the north side of Horseshoe Bend"

Could someone in the area of subject bridge post some pictures of the weight limit signs!

If a bridge had a 6000lb limit I do not understand why the bridge would not just be closed to all traffic.
AH64ID
Explorer
Apr 22, 2014
The Texan wrote:
NO correction is coming. The numbers I gave were the numbers given to me by the IDOT person in Cascade who was in attendance at the meeting. I double checked with him before I made the original post and he verified the numbers. If you want to believe the IDOT website, that is your prerogative. However, if you want to see their own mistake in writing, then compare the IDOT sign on the north side of Horseshoe Bend vs the IDOT website. Amazing none of the numbers are the same.....

Maybe you should check with them, current restrictions are NOT 9K/lbs an axle, they are 9TONS an axle.. Big difference, the current information is NOT what you posted.

As I stated it's not only their website, but the Port of Entry Supervisor. He needs to know a little about loads.

This is simply spreading information that does not agree with DOT. There is only one set of info that doesn't match, I suggest checking your source. It's possible they misspoke or you misunderstood.