Perhaps a bit off topic, but Joemikeb, part of your squirrel combat solution might be to escalate - i.e., plant more tomatoes. This is easily done if you compost your old tomato plants (and kitchen scraps, and most other yard waste minus grass clippings). Tomatoes need specific fermentation conditions for the seeds to germinate and low-volume composting will do the trick (low volume because the temperature won't get too high). Every year, volunteer tomatoes spring up all over our yard because of the home-made compost that I have spread. I weed out those plants that I don't want and keep the rest, producing tomatoes over a widespread area that simply overwhelm the critters (with me it's mockingbirds that are the challenge, not squirrels).
Who knows - with a sufficient number of tomato plants in place, perhaps the squirrels will ignore your Interstate entirely and you will have no more wire chewing. Plus you will have tomatoes like these. I took this pic yesterday afternoon with you in mind. My husband had scolded me for allowing most of our tomatoes to rot on the vine, but we have literally had five Interstate projects in progress simultaneously and no time to tend to the garden this year. So I promised him that I would whip up a batch of Cuban black beans, into which all of these ripe tomatoes went (and several pounds more). Simultaneously I made
our new computer table for the Interstate; cooking beans requires the gas stove to be on for 10 hours straight which means I must remain in the house. It's a good time to tackle
in situ Interstate projects.