Ir really depends on where I am. If I'm in the middle of NJ, where i usually find myself along US 1, then I wouldn't walk even if the restaurant was just across the street, as there is no safe way to cross US 1.

However, if I'm in a city with a more pedestrian friendly atmosphere, I'd be willing to walk up to 25 mins, weather depending.

Where I'm currently travelling to for work, anything within a 15min walk is acceptable to me. Outside of a 15min walk, I'd take a cab as it gets pretty far from downtown, relatively speaking.