From the I-375 Alternatives Study, this map gives a good look at how confusing driving Downtown can often be. The direction of traffic was determined decades ago when Detroit was busting at the seems with jobs and population. Now perhaps these directional streets are just more of a nuisance? Additionally, the historic street grid Downtown has been discombobulated as a result of expressway construction and you are often unable to follow particular streets through to different areas of the city without running into a dead-end at an expressway.