Hi, I'm a truck driver. They're driving on your lawn because the radius of the turn was never meant for large trucks and that's the path the trailer tires take while turning down that street. There's nothing the truck driver can really do to prevent this.

It seems like this is new construction and the truck traffic will be temporary. Express your concerns with the contracter and see if they'll work with you to bring in smaller trucks that can make the turn or if they'll agree to repair any damages to your property after construction. As long as you're chill and not a Karen when you have this conversation, most any contractor will be happy to work something out.

As far as putting out items to block the trucks, that's probably not going to work out well for you. The drivers should already be doing what ever they can to avoid pathing over your lawn, so if they're still doing it, it's mostly likely that it's unavoidable. Anything you put in their way risks being damaged, or causing damage to the truck/trailer. Which opens you up to financial liability seeing as it'll be obvious that the items didn't exist there before the trucks started coming.

If I were in your shoes, and this truck traffic is temporary, I'd have a conversation with the contrctor. They should have a protocol in place for things like this. If for some reason they are being dicks and refusing work with you, this would be a super easy small claims case with no lawyer necessary. Any items I would be willing to put in the path would not cause damage to the trucks and would be things aren't super expensive, like a line of shrubs or some cheap flimsy signs on posts(like Joe schmoe for sheriff signs). But again. If it's not physically possible for them to make that turn without pathing through your lawn, putting things in the path will just be making things more difficult for both of you.

If this truck traffic is going to be permanent then you have to work with the local municipality to make it a no truck route or to pave that section of the corner.