Nice work gloveman they should last forever , for people don't have a lathe heres a few more options for that I have seen to make tyre barriers, sorry no pictures
Cut tubes of foam rubber to height then finish off with a model kit tyre glued to the top complete with some white writing eg
goodyear they will possibly look out of scale on a strictly 1/32 scale track layout but hey they used truck and tractor tyres in the real world sometimes as well
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The most novel thing I have seen was a pile of lifesaver lollies glued together and painted in flat blackboard paint . Some lolly tyres also had a coat of white wrinkle finish paint over the top of the black so they looked like old (painted white) tyre barriers with a few extra wipes they can look like a car swiped them in a crash . Don't eat the painted ones !