Narrow, congested streets with not a lot of open space around it for run off are safer than wider, empty streets with lot of space around for when a driver might get off course. Why? Because a narrower street will keep the drivers focused on the road and potential dangers, whereas in the wider setting invites drivers to speed and drive recklessly in general, thinking that when they do a mistake they'll be safe anyways. This has been studied, however I don't have a link to the research papers at hand.