The plan of Manhattan is smarter than conventional wisdom concedes. Not a square grid, most of the streets run river to river instead of uptown and down, partly because the planners assumed that maritime commerce along the riverfronts would create more crosstown traffic. The blocks are nearly five times longer in the east–west dimension (avenue to avenue) than in the north–south (street to street), so most buildings avoid the low morning and afternoon sun, thereby ensuring plenty of light without too much heat. Because the grid sits at a twenty-nine-degree angle off of true north, potentially every building on every street can receive direct daylight every day of the year.