Quote of the Week: Grids vs Arterials

Overall, a gridded street network of two-lane roadways can accommodate both pedestrians in addition to much higher volumes of vehicles as compared to the large arterial/collector single intersection.  The superiority in capacity even holds when the grid system is compared against the arterial/collector without any pedestrian  accommodations whatsoever.  This research presented results in terms of vehicle delay and vehicle level of service; while not ideal in terms of truly understanding the impact of these large intersections in a complete urban environment, these results should instead be used to clarify many of the misconceptions that conventional traffic engineers have with regard to such large arterials/collectors intersections.   

Additional benefits of the grid system include real-time route decisions, increased levels of walking and biking, reduced vehicle speeds, and  as some recent research is showing, safer roadways for all users.  Critics may point out that the grid system increases overall vehicle delays for through traffic.  The analysis done as part of this study agrees with this assertion; however, the analysis is limited in that it assumes all trips begin outside the grid, travel through the grid, and then exit the grid.

From Supersized Intersections vs Gridded Street Networks: Comparing Capacities & Pedestrian Accommodation

Each week we feature a quote or an excerpt that clearly illustrates the benefits of new urbanist thought. 

Comments

[Darin]

Thanks for posting this -- it's an interesting read and I subject I think about a lot. I tend to live my life in a bubble in the central Downtown/Midtown Atlanta area and I think the gridded streets have something to do with that. They are so much easier to navigate as a pedestrian.

RE: "Critics may point out that the grid system increases overall vehicle delays for through traffic. The analysis done as part of this study agrees with this assertion; however, the analysis is limited in that it assumes all trips begin outside the grid, travel through the grid, and then exit the grid."

It's certainly time that cities realize the superiority of streets designed for multiple purposes (ped, bike, residents) rather than the single purpose of efficiently moving cars.

[R Paredes]

It would be interesting to see if people would actually pay more taxes to build more roads. (gridded system requires more public ROW's). I've seen lots of research on this subject but very little real world implementation strategies. I grew up in a "gridded street" system and I remember counting the days when we could move to a cul-de-sac. There is no "one size fits all" approach...