I started the expansion of my downtown area today, with its new Superstreets city street loops. The world isn't flat so I figured some my streets should not be either. Standard Superstreets vehicles in good condition can climb reasonable grades, but just to be safe I tested several of my bashed/custom SS/EZ vehicles on the roughed out streets shown here. All of my 18 wheelers had severe wheelspin making it up but they won't normally be these downtown streets. My bashed/custom built buses and cars (that's a '54 Caddy convertible) made it up with no problems, and just as important, down and around, just as easily. This street rises at a 10% slope: after the turn at the top of the city block it continues to climb at that rate until it reaches twice its height there: the level of most of my new downtown, which will be behind the row of buildings shown, will be roughly at the level of the roof of the two story building on the left in the photos.
I'd be interested in pictures and info from anyone who has built building layouts with sloped streets, and/or anyone who is running 'streets on slopes.