Most of the complaints I've read so far seem to center around a lack of data: apparently Google doesn't have elevation data for a sloped bridge, nor for whether

Most of the complaints I've read so far seem to center around a lack of data: apparently Google doesn't have elevation data for a sloped bridge, nor for whether a particular tunnel is walkable. It's an excellent idea and well-executed given the available data. I see a routing problem. I had assumed this tool would give longer routes to avoid steep inclines, but that's not always the case. Take the suggested case: Nob Hill to Russian Hill in San Francisco. Drag marker A to the corner of Vallejo and Powell (to the east of that big hill.) Now drag B to Union and Polk (to the west, and one block north of Green.) The resulting route includes some "very difficult" parts along Broadway when it could suggest one block over to Pacific and eliminate those black dots.