Yes, it's population density. In denser urban areas walking and transit become more practical and driving and dedicating space to parking become less so. Those

Yes, it's population density. In denser urban areas walking and transit become more practical and driving and dedicating space to parking become less so. Those areas are also more desirable to live in (or they wouldn't have the population to begin with) and that tends to drive up prices. Source: half-assed guess