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I just became aware of the possibility of raised crosswalks, which seem like a fantastic idea -- no gradient for pedestrians, and a speed bump to slow cars -- h
by mlinksva 8y ago
I just became aware of the possibility of raised crosswalks, which seem like a fantastic idea -- no gradient for pedestrians, and a speed bump to slow cars -- https://sf.streetsblog.org/2018/05/22/walk-sf-campaigns-for-san-franciscos-first-raised-intersection/ https://sf.streetsblog.org/2018/05/22/walk-sf-campaigns-for-...
I imagine a raised crosswalk would also be more expensive than a curb cut. Are there any advantages or disadvantages relative to curb cuts for various disabilities?
- Noumenon72 8y agoPedestrians are able to negotiate gradients more easily than cars, so this seems inefficient.
- mlinksva 8y agoThe inefficiency for cars is a feature. It means drivers will slow down and thus kill less. https://www.strongtowns.org/journal/2018/1/25/speed-kills-so-why-do-we-keep-designing-for-it https://www.strongtowns.org/journal/2018/1/25/speed-kills-so...
- duskwuff 8y agoSome pedestrians can manage a sloped curb at a crosswalk. Others may have a more difficult time of it. By contrast, all cars must be able to drive up and down a short slope. They must do so to enter most parking lots, for instance, so performing a similar maneuver at an intersection is no big deal.
- deleted 8y ago[deleted]
- andys627 8y agoSo many of our problems with regard to urbanism are rooted in making things efficient for cars over other users.
- kibwen 8y agoOne objection to omnipresent speed bumps would be their effect on ambulances. Unless one were to outfit ambulances with those nifty active electromagnetic suspensions, so that you could actually speed to the hospital without slamming the patient into the ceiling...
- civilitty 8y agoIn denser city environments where this would be installed, ambulances are already impeded in their speed and you likely wouldnt install this along a thoroughfare.
- dsfyu404ed 8y agoAt typical E-series based ambulance as found in the US spend 50,000 miles bombing down potholed gravel roads before needing major service and that major service is more preventative than anything else. People bouncing around inside and the ambulance box deteriorating are probably your first two limitations when it comes to ambulances driving fast over speed bumps.
- dalbasal 8y agoIt's interesting how much of this is just about visual design. make it look like the cars have to cross the sidewalk rather that pedestrians crossing roads.
- runarberg 8y agoReykjavík has a few of those, but they are amazing. They are one of the few places where cars actually stop for pedestrians almost immediately (way more effective then simple painted crosswalk). They also do wonders in slowing down the traffic as it reaches downtown (way more effectively then simple speed bumps).
- deleted 8y ago[deleted]
- megaman22 8y agoIn my experience, crosswalks are counter-productive. They are typically placed in terrible locations, with poor lines of sight, or at otherwise busy and attention-demanding intersections. It is far safer to avoid the hell out of marked crosswalks, and cross the street in other locations, where you can clearly see the flow of traffic, and pick a slot to cross that is safe.
- vlan0 8y agoUnfortunately, the blind and visually impaired rely heavily on crosswalks to cross the road. Attempting to cross without the safety of a crosswalk will certainly result in death.
- deleted 8y ago[deleted]
- bobthepanda 8y agoThe problem is that mid-block crossing only works if traffic is slow and there are appropriate gaps in traffic. As an example, most of America lives in places that have streets that are eight to eleven lanes wide, with posted speed limits of 55-65 MPH and effective speed limits ten miles an hour above that. In the suburbs, crossing a busy road is essentially a death sentence, and coincidentally these are also the areas that are generally the most poorly equipped with crossing facilities.
- megaman22 8y agoWell yeah, you don't cross highways. Most streets are not 8-11 lanes wide, particularly in places where anyone would ever be walking along them. Places where pedestrians are common are in-town, low-speed (25-30 mph posted) streets.
- bobthepanda 8y agoThe problem is we design our environments to be fundamentally hostile to walking between suburban neighborhoods, so only those who are desperate enough will walk. Usually this means the suburban poor, because cars can be prohibitively expensive. This usually results in scenarios that beggar disbelief, like this one: https://www.huffingtonpost.com/radley-balko/raquel-nelson-jail-for-jaywalking_b_905925.html https://www.huffingtonpost.com/radley-balko/raquel-nelson-ja...
- adilosa 8y agoIn fact, the ideas is thousands of years old. The ancient Romans had a concept of raised crosswalks in Pompeii: > Blocks raised on the road allowed pedestrians to cross the street without having to step onto the road itself which doubled up as Pompeii's drainage and sewage disposal system. The spaces between the blocks allowed horse-drawn carts to pass along the road. https://en.wikipedia.org/wiki/Pedestrian_crossing#History https://en.wikipedia.org/wiki/Pedestrian_crossing#History
- mlinksva 8y agoThat's awesome, thanks! Were raised crossing with spaces for cart wheels common around the world? Haven't cities everywhere had the sewage in the streets problem to varying extents for most of the time cities have existed?
- adrianmonk 8y agoImagine making a right turn at an intersection where you have to cross two of these, one after the other. Your car's tires are not going to make nearly as good contact with the road, making your brakes less effective should you need to use them. Turning, of course, puts lateral forces on the tires, making traction worse.
- sethhochberg 8y agoSounds like a feature, not a bug - you'd better slow down quite a bit to make navigating that situation safe and make sure you aren't exceeding the safe speed for that intersection. In the kind of dense urban areas where raised crosswalks have the most potential to make a difference in safety just by virtue of the raw number of people who use those street features, pretty much every improvement in some way contributes to lowering and moderating motor vehicle speed.
- Rapzid 8y agoTokyo is pretty darn dense and the normal, legal speed of traffic in most areas with crowded crosswalks exceeds speed bump speeds. City and traffic planners are sure to be concerned with increased congestion and reduced road throughput by adding speed bumps to intersections that are already in the most congested spots.. I disagree that making it less safe to navigate intersections at currently observed speeds is a good way forward. I also believe that if speed reduction is a identified goal there are ways to accomplish this without making navigation at current speeds more dangerous; such as psychological speed bumps.
- dsfyu404ed 8y ago>pretty much every improvement in some way contributes to lowering and moderating motor vehicle speed. Such as dedicated bike lanes that are divided from the rest of the road, raised sidewalks and other methods of traffic control that keep different classes of traffic from interacting? /s
- bobthepanda 8y agoIf you were to do all crosswalks at an intersection like this, it's much more common to just raise the entire intersection as a massive speed table. https://nacto.org/publication/urban-street-design-guide/intersections/minor-intersections/raised-intersections/ https://nacto.org/publication/urban-street-design-guide/inte...
- mc32 8y agoCurb extensions are an alternative which may be more practical. Maybe that in combination with smart road humps[1] which respond to speed, would deter speeders down oak and feel streets in SF. [1]https://hackaday.com/2017/08/14/smart-speed-bumps-slow-only-speeding-cars/ https://hackaday.com/2017/08/14/smart-speed-bumps-slow-only-...
- lancefisher 8y agoCurb extensions are awful for bicycles.
- dsfyu404ed 8y agoSpeed tables have the side benefit of being fun for specific minority of vehicle drivers when pedestrians aren't using them.[1] [1] http://image.fourwheeler.com/f/75606874+w660+h440+re0+cr1+ar0/ford-bronco-jumping.jpg http://image.fourwheeler.com/f/75606874+w660+h440+re0+cr1+ar...