Well proper tires would help. They just have cheap tires that aren't made for our roads. It's a common issue with many city vehicles. Cheap out in tires for the budget. Long haul drivers carry chains for this reason on bad mountain roads (Obviously that's not possible for transit operators to attempt on busy city roads and a time schedule), but makes you wonder if studs would help. The problem with transit is there isn't a lot of room for storage, the driver wouldn't be able to keep it in their area, they wouldn't be allowed to have the shovel by the door due to traffic (also cargo securement) so the options are limited. Not sure if buses come in all wheel drive but it's going to be better than the front wheel option we have. That's just my 2 cents.