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Another Reason Corner Curb Ramps Don’t Work Well

February 5, 2011 Accessibility, Downtown, Planning & Design 16 Comments

Pedestrians generally walk in a straight line, stepping over curbs as necessary to keep going in the same direction.

People pushing strollers, or using wheelchairs, have to go not in a straight line, but where the curb ramp is placed. Ideally ramps would be located where we could also continue in a straight line.

But most St. Louis intersections place curb ramps, not in the natural line of travel, but at the apex of the corner. On a standard intersection of two streets at a 90° angle the corner ramp does save money by requiring fewer ramps – four rather than eight.  The problem however, is the corner ramp has become the local default, even when it makes no sense to do so.

ABOVE: curb ramps at a downtown hotel drive direct you into the snow rather than a straight line

The example above is one where placing the curb ramps at the corners makes no sense at all. There is no opportunity to cross Washington Ave from either curb, the only direction to travel is straight ahead.  Most of the year it is just annoying that I’m forced nearly into the nearby vehicle lane.  When there is snow in the way I’m forced to go off the edge of the ramp and through some of the snow.

At other intersections I neatly got stuck because my line of travel was beyond the worn path of able bodied pedestrians.  The corner ramp is marginally acceptable when you have two crosswalks meeting at a single point.  The above ramps should have been constructed to permit a straight line of travel.  The cost would have been the same, maybe even less because a ramp is less complex in a straight curb as opposed to on a corner.

– Steve Patterson


Currently there are "16 comments" on this Article:

  1. JZ71 says:

    The problem isn't the ramp, the problem is the snow, or, more precisely, the slush and ice. In cities that deal with winter responsibly, the adjacent property owner digs out both the ramp and the curb after the city plows. Here, most property owners don't even clear the walks, apparently with no consequences, as in the sidewalk in the background! A path of travel is only as good as its weakest link. If curb ramps were the only things being neglected here, I'd see this as a big issue. But since more than half our sidewalks are still covered from the last storm, this is just one part of a much larger problem.

    • Wrong! If the ramps were placed in line with the normal path of travel the pile of snow at the curb line wouldn't be an issue, regular foot traffic would make sure the ramps are clear. Civil engineers in this town just routinely place ramps at the corner, even if it makes no functional sense to do so.

      • JZ71 says:

        Um, no. Unless someone shovels the slush, all you get are random footsteps, not an accessible path that a wheelchair or stroller can use.

        • Let's see, which of us can speak from actual experience on the matter? Oh yes, that would be me, not you. Other intersections the only path through the snow was the one clearned by numerours pedestrians. I have no expectation of the city to spend tax dollars ensuring every crosswalk is cleared of snow. Pedestrians do a decent job of that at crosswalks. I just need enfpgineers to understand that curb ramps should be aligned with the normal pedestrian route – especially in places where there is no logical reason for the corner ramp.

          • JZ71 says:

            Hey, I'm not doubting your expertise on ramps. My only point is that in my part of the city, where 90%+ of the public sidewalks remain unshoveled, ramps aren't the issue today, the frozen slush is! Until our community embraces both walking and rolling as viable forms of transportation, ramps will remain an afterthought, as will, apparently, snow removal. And no, I don't expect the city to spend tax dollars, but I do expect some PR and some enforcement of existing regulations. Now, all the focus seems to be on roads, roads, roads!

          • The post was specifically about the design of ramps, the snow just helped illustrate the problem. I don't want the point getting hijacked.

          • JZ71 says:

            I don't think I was hijacking your point: “Another Reason Corner Curb Ramps Don’t Work Well . . . Most of the year it is just annoying that I’m forced nearly into the nearby vehicle lane. When there is snow in the way I’m forced to go off the edge of the ramp and through some of the snow.”

            But since you want to debate ramps, not snow, I'll add two thoughts. One, two ramps (in the line of travel for both directions) take up more space than one set at 45 degrees on the corner. And two, in weather like this, curbs work better than ramps for the vast majority of pedestrians that aren't on wheels. The gutter is meant to carry water. A ramp, sloping into the gutter, doubles the width of the water most of us are trying to step over (not into). So, the argument becomes one of who “wins”? Who should have to deviate from their path of travel? The minority, on wheels? Or the majority, on two feet?

      • Wqcuncleden says:

        It makes sense when money is an issue. Instead of two they are getting buy with one. Which is better than none at all. Right???

        • I obviously failed to make it clear the ramps pictured serve only a single direction – crossing the hotel driveway. There is no way to cross the street to connect to either ramp.

    • jason says:

      I like the reference that “In cities that deal with winter responsibly, the adjacent property owner digs out both the ramp and the curb after the city plows. Here, most property owners don't even clear the walks, apparently with no consequences”

    • Wqcuncleden says:

      I agree 100% If the business owners here would get off their lead asses and clear the snow, the corner ramps WOULD work!

  2. Gpres says:

    Isn't there a required 4' landing at the top of the 5-7' ramp? This usually forces ramps to be placed at odd angles to avoid easements/expanding the sidewalk. That said, it would be difficult to place a ramp perpendicular to the street in the image above because of the proximity of that building facade.

  3. RobbyD says:

    It would seem to me common sense would dictate that the most effective ramps would allow pedestrians to continue along straight paths when crossing the street. That many ramps don't do this seems to this layman to be a result of poor or lazy design and miserly developers.

    I'm unsure of the real reason a pedestrian ramp would point a tax paying citizen using the ramp towards the middle of the street rather than the crosswalk. It doesn't really make any sense to me.

    • JZ71 says:

      There are actually several reasons. To be safe, sidewalks should be as flat and smooth as possible, to minimize the potential for tripping. Both the ADAAG and local engineering standards define a maximum safe cross slope, usually 2% or less. Curbs are actually an improvement over their predecessor, the ditch, and serve to define and separate the pedestrian realm from the vehicular realm. The ADAAG defines two kinds of acceptable curb ramps, one with straight sides and one with flared sides.

      The situation that frustrates Steve occurs primarily in urban areas, where the public sidewalk spans the full width, from the curb to the building fronts, usually on rectangular blocks. It's difficult to add ramps with straight sides since there's usually a confict with perpendicular traffic at each corner, and adding two ramps with flared sides to a corner creates their own set of trip hazards, plus there are often storm sewer inlets that conflict with the ideal ramp locations. (In less-urban areas, where there are tree lawns and the sidewalk is detached from the curb, ramps with straight sides seem to work well since they don't present a trip hazard to perpendicular pedestrian traffic.)

      In more-urban (CBD) areas, the 45 degree ramp that Steve shows is, at best, a compromise solution. Yes, it minimizes the number of facets, and thus minimizes trip hazards, but it also wants to redirect pedestrian traffic into odd paths, plus it lets the apex of the corner lose much of its present definition, which can endanger stationary pedestrians.

      I don't disagree that new projects should meet all applicable standards. If you're tearing everything out, it's not that hard to juggle all requirements. The challenge in the CBD is that most ramps are a retrofit, done with limited funds, removing a minimal amount of existing paving. Things like storm sewer inlets, light poles and fire hydrants CAN be moved (if you have the money to do so), but rarely are since doing so would increase coists by multiples (3X, 8X, even 20X). As with many civic projetc, it's all about stretching the dollar – we can do 20 “perfect” projects or 80 or 100 imperfect ones (for the same money).

      • In the example pictured at a hotel driveway there are no sewer inlets or fire hydrants in the way. Ramps in the direction of pedestrian travel would have been just as easy. Engineers here have gotten it in their heads that ramps belong at the corner. I'm trying to undo that thinking so they are only placed at the corner when circumstances don't allow them to be more direct.

  4. Eric says:

    There are new standards provided from the access-board.gov for Public Rights-of-way that consider existing intersections that may require a more thoughtful solution than the two ramps indicated in the ADA. This new standard has been adopted by several agencies already as best practices. I do believe that corner ramps were a design to reduce costs, but create some very dangerous situations. Poorly designed ramps, as indicated previously, can force people using mobility devices into traffic lanes and in worse case scenerios throw people out of their chairs where the ramp meets the street (streets look flat, but are arched to allow for water to drain into the gutters). For people with vision disabilities, these corner ramps can redirect them into the intersection and make it more difficult to realign with the actual cross-walk. It is far better to have separate ramps that align directly with the cross-walks. Good design can eliminate trip hazards and work around exisitng street equipment. (http://www.architecturalaccessibility...)


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