How to Quantify Benefits of Trees

Photo of birch trees
Lake Carlos Park, Minnesota

It seems obvious that trees impact our communities in a beneficial way by providing shade and lowering temperature, absorbing carbon dioxide, and intercepting and absorbing rainfall. But quantifying these benefits can be challenging. Fortunately the USDA Forest Service “provides urban and rural forestry analysis and benefits assessment tools” that can help us. The USDA developed these through a public-private partnership with Davey Tree Expert CompanyThe Arbor Day FoundationUrban and Community Forestry SocietyInternational Society of Arboriculture, and Casey Trees. What surprised me is that these tools known as i-Tree have been around since 2006.

You can access the website to learn more about these tools here: i-Tree Website. The i-Tree site lists a suite of tools for assessing impacts of both individual trees and tree canopies. And there is a tool to help you select the species based on your location.

The i-Tree website also has a lot of resources to help you in learning how to use their tools. You can visit their support page to access manuals, guides, workbooks, and reports from users. For example, they list a link to a Story Map site set up by Abington Township Montgomery County, Penn., a community which made use of the i-Tree suite. And while this community is in the United States, the use of i-Tree is not limited to the U.S. The i-Tree site also lists information regarding its use internationally with examples of its use in other counties.

Other resources to check out include their User Forum, LinkedIn account, 2024 i-Tree Open Academy. And finally if you have time and opportunity you could attend the following conference highlighted on the i-Tree site: the 4th European i-Tree Conference & Urban ReLeaf Conference which will be held June 19-21, 2024, in Dundee, Scotland.

Logo for i-tree, a graphic with a tree and city silhouette.
I-Tree Logo


Can AI Be Used to Check Stop Control Warrants?

person at a computer with back to viewer

For some time I have been thinking about how AI could be used to assist civil engineers and the public works industry. While I have several ideas, one obvious application I’ve thought about is using it to check all-way stop control signal warrants as defined by the Manual of Uniform Traffic Control Devices (MUTCD). Since I was taking a class in AI with homework asking us to create our own GPTs using ChatGPT, I figured I’d use this opportunity to try out the MUTCD stop warrant idea. While an analysis by AI obviously cannot be used in place of an actual engineer’s analysis, I thought others might be interested in seeing the result of this test of its abilities.

I’ll include below the results so even if you don’t have a subscription to ChatGPT you can see how it performed. If you subscribe to ChatGPT, you can try it on your own at by uploading a txt file with data similar to my example below using the “Stop Control Warrant Analysis” GPT – this is different from using ChatGPT as it is a custom GPT I created specifically to analyze stop control warrants per the MUTCD.

To use it I first prepared a text file with the data I figured the GPT would need to perform the analysis. This is the information I put into a TXT file using Notepad then saved it. By the way, this is all made up information for a fictitious intersection:

Name of Intersection: Main and 22nd
Intersection Location: Anytown, IL
Minor Street Name: 22nd street
Major Street Name: Main street
Number of legs in the intersection: 4
Number of crashes in a 12-month period: 40
There is adequate sight distance.
An all-way stop control could not serve as an interim measure.
The number of units per hour in a typical 8-hour day on the major street is 5000
The number of units per hour in a typical 8-hour day on the minor street in that same hour is 300.
The 85th percentile speed limit is not over 40 mph
There is a need to control left turns
These are not through residential collector streets.
Pedestrian and/or bicyclist movements support the installation of all-way stop control.

Next I went to the Stop Control Warrant Analysis GPT and typed in this prompt: “Can you help me figure out if my intersection needs a stop sign? I have attached a text file with my data.” And I uploaded my TXTfile. Below is a screenshot showing this along with the output from the GPT.

Screenshot of GPT output
Output from Stop Control Warrant Analysis GPT – click the image to enlarge it.

I tested it again by starting a new session and uploading a new text file with slightly different data noted below – again all fictitious:

Name of Intersection: River and 22nd
Intersection Location: Anytown, IL
Minor Street Name: 22nd street
Major Street Name: River street
Number of legs in the intersection: 4
Number of crashes in a 12-month period: 4
There is not adequate sight distance.
An all-way stop control could not serve as an interim measure.
The number of units per hour in a typical 8-hour day on the major street is 150
The number of units per hour in a typical 8-hour day on the minor street in that same hour is 100.
The 85th percentile speed limit is not over 40 mph
There is not a need to control left turns
These are not through residential collector streets.
Pedestrian and/or bicyclist movements do not support the installation of all-way stop control.

Below is another screenshot showing my prompt and the response:

screenshot of output of GPT
Output from Stop Control Warrant Analysis GPT – click the image to enlarge it.

For each you can see I have asked the GPT to add the language at the end so if anyone tries this they realize it cannot be used in place of an actual analysis by a professional engineer. I only set it up to test out how well it might work with completing this type of analysis and would not want anyone to think it is doing actual engineering – it isn’t. There also might be better ways to use other technologies to do the same thing. However, all of this was done just by telling it what I wanted it to do and giving it the information it needed to do it.

In the future I will continue to test out different applications to see how useful it might or might not be. And if I have anything that looks interesting I’ll continue to share here. If anyone else has tried creating something for engineering or public works, I’d also be very interested in exploring it.


Using AI to Generate Images for Public Works – Post 2

water color sketch of a water valve
AI-generated image of a water valve

In the first post on this topic I introduced the Midjourney AI tool which can be used to generate images. In this post, I’ll talk about a few more image generating tools I have tried. The first is Canva. This tool is fairly easy to use; however, you will need to make a free account to access it.

If you decide to try Canva and visit their site, you will find a lot going on there because Canva does a lot more than just generate images from text. To find the AI tool on their site, you can click “Apps” and when the next screen comes up look for “Text to Image.” Once you click that a box pops up asking if you want to use this in a new design or existing design. You can click “use in a new design.” If you do this, you’ll see they offer a drop down with a long list of items from which you can choose. When I am creating an image I usually want a 512 x 512 pixel image, so I choose “Custom Size.” If you make this same choice, you can indicate your image size and then click the button “Create New Design.”

screenshot of the Canva text to image app
Screen shot of the Canva Text to Image App

Next, you should see a screen like the one shown in the image above. There is an area on the right with the blank canvas and a small input area where you can type the description of what I want. Initially I tried “a person putting their garbage can at the edge of the road.” For the style I left it at “None.” After a short time, the image below is what it generated which wasn’t quite what I had hoped for. A person is only in one of the images, and the can is actually in the road.

Four images of a blue garbage can sitting in the road. One image has a woman in a red shirt and black pants crouching down near the can.
AIi-generated image of a garbage can along a road from Canva

So I tried again this time choosing the “Dreamlike” style. The images generated were a little closer to what I was looking for, but the person was a small child in two of them, and the one with an adult did not look realistic. Here is how it came out:

four images showing garbage cans in the road. A small child in standing near a can in two of them while a woman is near one in another
AI-generated image of a garbage can from Canva

After not really getting what I was looking for I tried a different image. This time I typed “a stream winding through a field of grass and trees.” I left the style at “none.” The image generated which I included below turned out close to what I had envisioned. Although if I wanted to use this to illustrate a stream in my area, I would need to try again and add text to indicate no mountains.

four images showing a stream winding through a field of grass with some trees. Three images have mountains in the background and the remaining one has a waterfall.
AI-generated image of a stream from Canva

Another image generating AI often talked about is DALL-E 2. This AI is brought to you by OpenAI – the same organization which offers ChatGPT. Just like with Canva, you will need an account to try out DALL-E 2. Once you log in, this is how the site looks:

Screen shot of the DALLE2 site
DALL-E 2 Website

In the prompt line I typed in the same text I tried with Canva: “a person putting their garbage can at the edge of the road.” DALL-E 2 generated four images, the same number produced by Midjourney and Canva. What I really like about the images generated by DALL-E 2 is they download with a DPI resolution of 300. The other tools download at a smaller size, and I always have to bring them into my image editing software to upsize them. Also, almost all of the images generated by DALL-E 2 were close to what I was looking for. I added below the one that I thought was best.

image of a brown garbage can at the side of the road with someone's arm resting on top of it. There is a car in the background.
AI-generated image of a garbage can by DALL-E 2

And just for fun, here’s another image I generated on DALL-E 2 a while ago using the following text: “a red fire hydrant van gogh style,”

an image of a red fire hydrant
AI-generated image of a fire hydrant by DALL-E 2

Of the two tools discussed here, I had better results with DALL-E 2. Plus there is the added bonus of not having to process the images in an image-editing software to get them to the resolution I need. Both were free to use, although Canva has some terms of use you may want to check out if you are using the images you create on their site for work.


Can AI Help Fix a Water Main Break?

Robot in orange suit standing on a wet road looking down with cars parked on the side of the road

Maybe you’ve heard about AI, and maybe you haven’t, but odds are you most likely will. There are many types of AI tools being developed. One example is ChatGPT, a text-based tool providing answers to questions in a conversational manner. Since ChatGPT launched late last year, it seems everyone is discussing Artificial Intelligence (AI) and what it means to society. Being in public works, I can’t help but wonder about all the impacts to our industry

So today I thought about using the ChatGPT tool to see if it could help me figure out how to fix a water main break. After all, this is a common issue that comes up in public works, and I was curious to see how AI would respond. Could AI take the place of that wise, seasoned employee? Based on its advice I wouldn’t be ready to send it out to the jobsite just yet. Here’s how the conversation went:

My input: How do i fix a water main break?

ChatGPT’s answer: Fixing a water main break typically requires the expertise of a professional plumber or water utility company. It can be a complex and potentially dangerous task that requires specialized equipment and training.

Here are some general steps that may be involved in fixing a water main break:

  1. Shut off the water supply: The first step is to turn off the water supply to the affected area. This may involve turning off a valve or shutting off the main water supply to the entire property.
  2. Locate the break: The next step is to locate the break in the water main. This can be done by observing signs of water damage or by using specialized equipment, such as listening devices or cameras, to pinpoint the location.
  3. Excavate the area: Once the break has been located, the affected area will need to be excavated to expose the damaged section of pipe. This may involve digging a trench or using other methods, depending on the location and accessibility of the break.
  4. Repair or replace the pipe: Depending on the extent of the damage, the pipe may need to be repaired or replaced. This can involve cutting out the damaged section and replacing it with a new piece of pipe or using specialized equipment to seal the break.
  5. Test the repair: After the repair has been made, the water supply should be turned back on and the system tested to ensure that there are no leaks or other issues.

It is important to note that these are general steps and that the specifics of the repair process may vary depending on the location and nature of the water main break. In any case, it is recommended that you consult with a professional plumber or water utility company to ensure that the repair is done safely and effectively.

My assessment: The AI gave a fairly simple explanation. To be fair, I didn’t give it a lot of detail regarding my expectations for its answer – I just asked a question. And I’ve found that being more detailed in your expectations for the output can make a big difference in the response. However, even with the simple steps provided by ChatGPT, I thought it left out a few critical items. So I followed up:

My input 2: In general that is good, but I think you should add a step where you call for utility locates before digging. That is really important. You should also add to the testing section a note about the need to test for water quality before allowing people to drink the water after the repair.

ChatGPT’s answer 2: You are absolutely right. Before excavating the area, it is important to call the local utility locating service to identify any underground utility lines that may be present in the vicinity of the repair site. This helps prevent accidental damage to other utility lines during the excavation process, which could result in further disruptions to utility services, property damage, or even personal injury.

Additionally, after the repair has been made and the water supply turned back on, it is important to test the water quality before allowing people to drink or use the water. Water quality testing can help ensure that the water is safe and free from contaminants that could be introduced during the repair process. This testing may involve taking samples of the water and sending them to a laboratory for analysis, or using on-site water testing equipment to check for things like chlorine levels, pH balance, and other parameters.

Thank you for bringing these important points to my attention.

My assessment: The AI was very accepting of my suggestions and polite in its response readily incorporating the information. I also liked that in its first response it emphasized the need to consult a professional. I’m going to keep testing out the tools, and as I do, I’ll try to share some of it in future posts. I’m also interested to see what others are doing with AI to help support public works and government work so reach out if you want to share!


April is National Safe Digging Month

Yes construction can and does take place all year long. But in the Midwest where frost can get down to about three to five feet, activity tends to drop off as winter sets in. We typically use this time indoors to plan for next year’s projects, and as the robins show up and warmer breezes blow in, we start setting up project schedules for the year. But as we kick things into gear, we want to remember the importance of calling for utility locates before we sink any shovels into the jobsite. To help promote this important step in the construction process, the Common Ground Alliance launched its annual support of National Safe Digging Month.

You can check out their website for resources and graphics that you may be able to use for your operations. And if you are a community, you may be able to use some of the graphics to promote calling before digging with your residents. It’s surprising how easy it can be to hit utilities sometimes doing things you wouldn’t even think would cause a problem. I was on a jobsite once where the contractor was securing the site at the end of the day. One of the workers was pounding in metal fence posts to hold up the orange construction fencing around the site. He pounded one right through a communication cable. Some of the crew ended up having to stay until the utility could repair the cable. The worst part of it was after he broke it, he noticed the line had been marked – he had pounded the pole right into the orange line. He most likely didn’t think pounding a metal fence post could break it like digging could. It was a good lesson to me that before you do anything in an area of a locate where you are putting something in the ground, you need to locate that utility first or move away from it if possible.

National Safe Digging Month logo showing someone planting a tree with a shovel.

Free and Online Access to Building Codes

Did you know anyone with access to the internet can check out current building codes at the International Code Council (ICC) website? It’s true! I am really excited about this because when I first started in the industry, I only had access to the physical books, and I always thought how much easier things would be if I could use and refer people to a digital version.

Well now we all can – building professionals and property owners and renters – basically everyone. All you have to do is visit the ICC website at and check out any of the 15 codes they offer along with other related publications. They even have different years of the code available. Of course they offer a subscription service with more features which is probably something a building professional would be more interested in than a property owner.

When you get to the site, you can filter the codes in the menu on the left which you can see in the image on this page. You can also go to a specific year by clicking the drop down at the top and choosing the year and version of code. To view a code which shows up in the display, just hover over the graphic of the title and when you see “View as Basic” click on it. The site will take you to the code. You can check out different sections of the code by clicking on the list of sections on the left of the screen.

One important thing to keep in mind is even though the codes are there for free for us to read, they are still under copyright. So in accessing and using them we need to make sure we don’t infringe on the ICC copyright.