icy driveway and liability

[Sasha Fukuda]

So, i have a triplex in a town half an hour from my house. I kept on the same person to plow the snow as had done it in the past. I never actually signed a written contract with him. Currently there's a layer of ice on the driveway that most of the other driveways around it don't have. Apparently it was due to a thin layer of snow that then froze. This has resulted in several problems for me.

1) I got an email from a tenant saying that the driveway needs to be salted and sanded. This is my first investment property and i don't live there, and this is something that i'd just never thought about due to my inexperience. I brought salt and sand to the property and fixed the problem. I also let all the tenants know that there's salt and sand in the shed, and that they can use it as needed. However, this situation makes me nervous. I'm not there most of the time to judge the quality of the snow plowing, or whether it needs snow plowing, or to salt and sand the driveway myself. Even if a tenant contacts me and says it needs plowing after a thin layer of snowfall, all i can do is talk to both them and the snow plow guy, listen to their explanations, and try to figure out who's right. Thus, I feel like i have limited control over whether the driveway is icy. Yet, according to the leases, i'm responsible for the driveway. If someone slipped and fell, i might be liable. This is especially a concern because some of my tenants are disabled and might be more prone to slipping and falling than able bodied people. Yet, i'm finding myself having to rely on the snowplow guy and the tenants salting and sanding their own driveway to ensure that it's safe. This seems very risky to me. 

2) One of my tenants is saying that the ice at the entrance of the driveway has damaged the exhaust system of his car and is demanding compensation for the cost of the repairs. There is an ice build up there. It is a bump going into or out of the driveway, but nothing i would have thought was anything more than a minor inconvenience. I go in and out of the driveway whenever i visit the property and i've never regarded it as a serious problem. How do i respond to this and is this even the sort of thing that i can prevent in the future?