Yes, apparently it is different since everywhere that I've lived cars drive across the sidewalk quite frequently - whenever the driver wants to go up a driveway to park, or enter a business parking lot, gas station, etc. It's also common for those who are walking (or riding a bike) on a sidewalk to have to cross a road unless they plan to just endlessly circle the same block. Nor is it that uncommon for drivers to inadvertently go up on a sidewalk - if drivers were all perfectly in control of their vehicles we wouldn't have this discussion of relative safety. Locally the last few bicycle fatalities of which I'm aware were all either on a city sidewalk or on the shoulder of a road without sidewalks.