sidewalk buffer widths

One of the elements of street design is the width of sidewalk buffers, and how these are presented in design standards. The sidewalk buffer is the area between the curb and the sidewalk. The city calls sidewalk buffers ‘planting strips’, and this is often how they are used, but it is not the only use, and in more urban areas, there are often multiple uses of the sidewalk buffer.

I did a sampling of sidewalk buffer widths in the central city, and a few other parts of Sacramento. I am not claiming any insight into the overall pattern. The city does not have a publicly available database or GIS layer of sidewalk locations and widths, let alone locations and widths of the buffers. I have heard rumors that they are developing one, but I have been hearing that rumor for the last ten years, so I’ve become doubtful.

Typical buffer widths in the central city range from six feet to nine feet, with seven feet being the most common. With huge mature trees, the narrower buffers are too narrow of the trees, and the sidewalks have had to be modified. The photo below shows an example, and these situations are everywhere.

sidewalk narrowed for tree roots, Q St near 14th St
sidewalk narrowed for tree roots, Q St near 14th St

Sidewalk buffers in other areas of the city range from zero – no buffer at all, these are called attached sidewalks – to three or four feet. Few areas outside the central city have wider buffers, but there are exceptions. Of course there are areas of the city that don’t have sidewalks at all, so of course don’t have buffers. You might think this is an earlier pattern of development, but all the the areas with no sidewalks and no buffers were built long after the streets of the central city.

The ‘fabulous 40s’ neighborhood has attached sidewalks, not what one would expect. I think the reason is that the developer and homeowners knew there would alway be trees on private property. And that is true, here. But in many lower income neighborhoods in north and south Sacramento, you will see attached curbs without buffers, and a paucity of trees because the owners or renters were not able to care for or replace trees. So the sidewalks are unshaded, and the streets look run down, and the heat island effect is noticeable. As if that weren’t bad enough, rolled curbs are common and encourage drivers to park part way onto the sidewalk, further narrowing the already narrow sidewalks. That is why we need wide sidewalks and sidewalk buffers in the public right-of-way, maintained by the city for the benefit of all.

The interesting exception to narrow buffers is a six block area in Poverty Ridge, between 22nd and 24th streets, and T and W streets. 23rd and 24th streets have fifteen foot wide buffers, as does U, V, and the north side of W street. The V street wide buffer extends to 20th St. Here are some photos of those wide buffers. As you can see, the uses of the buffers are variable. Old trees, young trees, gardens, rock gardens, sitting areas.

The total width of the public right-of-way on these streets is about 76 feet, and the sidewalk and sidewalk buffer is about 22 feet, leaving about 32 feet curb to curb for the roadway. Parking reduces that width by another 14-16 feet, leaving about 18 feet of travel way. Two vehicles can easily pass in the street, but it feels tight to the drivers, so they really slow down to pass. Except for commercial trucks and oversized SUVs and pickup trucks, most vehicles are 6 feet wide. This is what a street should be like! A narrow travel way that enforces slow driving. And it certainly could be even narrower.

The public right-of-way on surrounding streets is the same, about 76 feet. With sidewalk of 7 feet, a buffer of 7 feet (or less), and a parking area of 7-8 feet, that leaves a travel way of about 32 feet. Is it any wonder that many drivers speed on such streets? They are far too wide to be safe. It is wasted space that could be allocated to other uses. More impervious surface producing more stormwater runoff, and more dark pavement producing more heat island effect.

Which street would you rather live on? One with 15 foot buffers, trees and other greenery, and slow moving motor vehicles? Or one with 5 foot buffers hosting unhealthy trees, or no trees, and fast moving motor vehicles?

If you have heard of Poverty Ridge but have not walked the streets there, you may have the impression that wide buffers and narrow streets are only for rich areas. But these blocks are actually not the top of the ridge, where the mansions are, but rather a middle class to upper middle class neighborhood. This is the kind of place that everyone could have, if the city made it part of their street design standards, rather than an unusual exception.

So, my recommendations for the street design standards update is a minimum width of eight feet for sidewalk buffers/planting strips. A minimum. Wider would be better, wider would be great. And the travel way on local streets should never be more than 18 feet, which enforces slower speeds through perceived friction.

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