With the important timber industry in Minnesota in desperate shape, and our legislators calling for “out of the box” ideas, I have formed my own “shovel ready” stimulus plan. My plan is to replace metal roadway signpost throughout the State with homegrown wooden posts, harvested and manufactured in Minnesota.
This idea is not new. During a recent trip to Salt Lake City Utah to visit my son, I was impressed that all the highway and street sign posts there are made of wood. Anyone who has been to Wisconsin may have noticed that they too use wood for all their signposts needs.
I have done some leg work on this proposal. I first contacted Leslie Mc Inenly, who is an information specialist with the Minnesota Forest Resources Council. From there I was directed to John A Rajala, who is a member of the council and runs a large wood operation in Deer River, MN. He informed me that all posts must be treated with a preservative, and that there are 6 companies in the State of MN that do post treating, including Land O Lakes Wood Treating in Tenstrike, Turtle River Wood Treating in Turtle River, Page and Hill Wood Products in Big Falls, and Lake States in Duluth…all Northern Minnesota companies that would gain from this initiative. His comments also included that wood maybe a bit more expensive than metal, but was a renewable resource. He thought RED PINE should be considered, as it is treatable, abundant in Minnesota, reasonably priced, and in need of markets.
Next I contacted the Signing Engineer for the State of Wisconsin, Matt Rauch. Here are his comments:
I am the State Signing Engineer for Wisconsin DOT and I would like to respond to your questions on wood sign posts. Most of the signs Wisconsin installs are on wood 4 x 6 posts that are CCA treated. We have used wood posts for many years and we feel they offer more benefits than steel posts. They are less expensive, faster and easier to install and can handle a lot of wind loading. For example, we can get a maximum of 20 S.F. of sign area on a single wood 4 x 6 post where we can only get a maximum 9 S.F. sign area on a steel post. Also, with the cost of steel skyrocketing in recent years, wood posts have even proved a better value. We have a statewide wood sign post purchasing contract with Lake States Lumber out of Duluth. The wood is typically southern yellow pine.
As for safety, we are required to drill to 1 1/2" diameter holes at the bottom of the post in the 6" face so the post will break away properly when impacted.
As for problems with wood posts, occasionally we get some that warp that have to be replaced. We had a problem about 4 years ago with ACQ treated wood posts being used instead of CCA. The additional copper in the ACQ treated posts caused a reaction with the aluminum signs and we actually had aluminum signs rot off the posts. We have since corrected that problem and have gone back to CCA. We have purchased some posts with MCQ treatment from Lake States Lumber and have started to test those out. The MCQ is supposed to be both environmentally friendly as well as not corrode aluminum signs.
Hope this helps. If you have any questions, please feel free to let me know.
Matthew R. Rauch, P.E.
State Signing Engineer
WisDOT Bureau of Highway Operations
Traffic Engineering Section
(608) 266-0150 (office)
(608) 246-5305 (Sign Mfg. Shop)
(608) 516-6319 (Cellular)
With optimism, I began to contact people in the Minnesota Department of Transportation (DOT). It is here where the objections began to fly. First I was told that because of frost and winter, that wooden signs are difficult to remove and wouldn’t be prudent. Since Wisconsin has winter, I again contacted their signing engineer who responded that with carbide blades and using some salt around the base of a broken post, in most cases they can remove it. If they cannot, they temporarily use a steel post attached to the broken post until spring when it can be easily removed.
After overcoming this barrier, I was saddled with a litany of reasons why wooden posts would NOT BE CONSIDERED by the Minnesota Department of Transportation. Here is an excerpt from the email I received from Mike Weiss from the DOT…
>>> Mike Weiss 12/30/2008 10:47 AM >>>
Although the Wisconsin DOT has used wood posts for sign for years, they are now beginning to switch to steel sign posts for larger signs instead of using wood posts. Contact Matt Rauch at "firstname.lastname@example.org". Also, New Jersey years ago quit using wood posts due to disposal issues.
1) Mn/DOT has never done any cost analysis of using wood posts since we use galvanized steel flanged channel posts for our sign structures.
The only wood posts that have been used on state highways is at railroad crossings and those posts are installed and maintained by the rail authority.
2) I am not sure what agencies would consider using wood posts since there appears to be the issue of disposal when the posts would eventually have to be replaced
3) Not aware of any safety issues, BUT there are issues with wood posts being hit in the winter and difficulties replacing them in frozen ground. Talk with Matt Rauch about this.
- Replacing wood posts in the winter months
- Wood posts could splinter when hit
- Steel posts can be driven in frozen ground
Mn/DOT has discussed wood vs flanged steel posts a few times in the past 10 years. As an agency we have decided to NOT switch to wood sign posts based on the following:
- Wood posts basically break apart when hit. Once broken over, they would be a nuisance to remove the stubs AND it would be costly to replace wood post sign structures during the months the ground is frozen.
- Disposability of hit posts OR old posts when they need to be replaced. Wood posts are treated and, as such, would likely require special disposal methods.
- Galvanized flanged channel post structures typically remain in place for a long period of time (up to 30 years or more).
- Frequently hit signs in the Metro area new have breakaway couplings at the base, thereby requiring minimal maintenance if hit (also not required to call Gopher One Call for utility spotting since the stub post in the ground is reusable).
- Mn/DOT has used galvanized steel flanged channel posts for over 40 years. We had to crash test our sign structure design in the late 1980′s at a cost of over $30,000. With this expense, we feel we have a vested interest to continue their usage.
- Flanged channel steel posts can actually be driven into frozen ground (if necessary) to expedite reinstallation of a critical sign.
- Our sign trucks used statewide are specifically ordered to accommodate flanged channel steel posts of varying lengths AND all of our equipment statewide is specifically made to drive and remove flanged channel sign posts.
- Flanged channel sign post structures are easily modified, if necessary. They are also fairly easy to erect with the specific equipment that Mn/DOT owns.
Cities or counties can use wood posts for signs, BUT the wood post needs to meet Federal breakaway requirements and be a certain type of wood. Again, Matt Rauch could give you some background on the breakaway issues and the type of wood sign posts that the Wisconsin DOT uses./
The final email came from John Sampson, MN DOT Office of Environmental Services who wrote to inform me of the big problem the State of Minnesota would have in disposing of treated timber wood signposts. Apparently CCA is what is used to preserve wood now and a new preservative (ACQ) which is suppose to be safe is being tested, but has copper environmental problems. Here is his email:
FYI, please keep in mind that the laws and regulations are different in Wisconsin than in Minnesota. For one thing, in Minnesota we are required to test materials such as treated wood before disposal and then we must "manage" them accordingly. Years ago the federal government gave an administrative exemption to CCA treated wood from the Federal Hazardous Waste Regulations. Minnesota decided to be more stringent and did not adopt that exemption. That is why we are required to test the material before disposal. Several years ago we stopped purchasing CCA treated wood because we found that the vast majority of samples that would be tested would test as hazardous materials or hazardous waste. That means that we would have to dispose of any CCA treated wood in a special hazardous waste facility. At the time there were no such facilities in Minnesota with the closest being in Illinois.
We also began using ACQ treated wood but stopped when we discovered that the amount of copper leaching out of the wood would be much greater than the soil clean-up standards for copper in Minnesota. Since Mn/DOT is regulated by the MPCA and EPA as any other entity would be and is liable for its actions, we developed what we call our Hazard Evaluation Process to help us minimize our risk of environmental liability. This evaluation tool is used to determine the level of our environmental liability associated with a material. Materials with very low environmental liability risk could be used without restriction. Materials that have some or a moderate risk of environmental liability might be allowed to be used but with some restrictions. We would not use materials with a high environmental liability risk. At this point I have not heard of MCQ. Perhaps that is a trade name for a particular product. Suffice it to say, we have not evaluated MCQ.
One other point I would like to make is that the above stated policies are for Mn/DOT only and are only for environmental considerations. Local units of government such as cities or counties are free to make any decision they choose regarding the use of treated wood.
If you would like to discuss the environmental concerns we have with treated wood feel free to contact me or Brian Kamnikar (Ph. 651-366-3617). Brian heads up the Unit in my Section that deals with these issues. Thanks!
John M. Sampson, P.E.
Minnesota Department of Transportation
Office of Environmental Services
Director, Environmental Analysis Section
395 John Ireland Blvd.
Phone: 651.366.3622 Fax: 651.366.3603
After all of this going on for over a two month period, here are my perceptions. There maybe drawbacks to using wood sign posts, but our neighboring State of Wisconsin, the State of Utah, and other states have apparently overcome these drawbacks. I am sure Wisconsin and Utah are very careful to consider their environment and have necessary protections from whatever hazards the treating of wood posts may have. I sincerely feel this proposal still considers merit. Drive along a typical stretch of highway anywhere in the State and count the number of steel posts being used on signing. Imagine now if all of these steel posts were replaced by wood, wood grown and harvested by Minnesotans in our State, cut by sawmills in our State, treated by companies in our State, helping our struggling forest industry of Northern Minnesota. (by the way…Wisconsin gets their wooden posts from Lake States in Duluth/Superior). What do you think? Is this something worth pursing? I would be interested in your thoughts. In the mean time I will send this proposal to several local legislators and will let you know in the coming weeks where this goes.