02-01-2016, 09:27 AM
I feel that concerns about close-to-roundabout crosswalks holding up the entire roundabout are fairly exaggerated. Take the roundabout at Kraus by Conestoga Mall. It's one of the smallest roundabouts you will find, and when I cross it on my daily commute, I do occasionally find that A vehicle has to pause for me to cross, but even this exceedingly small roundabout has the space for that vehicle to avoid blocking traffic behind them. The time it takes me to cross the 2-car-wide lane (the most lanes we have for our region's roundabouts)? About 2 seconds. Let's say that it takes 5 seconds for a really slow person. Now, at a standard, non-restricted walking speed, making a person go on a 60m detour takes an extra minute of time. Two, if they are a really slow person. So, on one hand, we can delay cars for 2/5 seconds close to a roundabout, or ask the pedestrian to take a 60/120 second detour (The equivalent of their 2/5 second journey holding up ~30 cars simultaneously, and expecting that no cars would be held up for any seconds at the detour crossing, which is even less likely due to higher speeds). This doesn't seem very beneficial for anyone in reality, only in appearance.
As for why we block out the central portion of a roundabout with a hill/tall grass/artwork, it helps to slow down cars by making it seem like a larger obstacle, and critically it removes non-useful information. When entering a roundabout, we want a driver to look left and right at their crosswalk for pedestrians, and to the left for cars. That's it, period. They should not choose to enter or not enter a roundabout because of what is happening at future exits; by the time they arrive, most happenings will have ended or changed. We especially don't want someone looking straight ahead for the entrance directly opposite them, and missing the goings-on happening at their car, or looking at the exit directly opposite them [when entering], seeing it clear, and then having that information guide them into being less likely to check that information at the critical time [when you've actually gotten to that exit]. It's like a driver looking at a crosswalk when turning left, seeing it empty, then focusing on cars coming at them, and going through when the cars clear, only to screech to a halt for a pedestrian well into their crossing, but one that started after the initial glance that the driver used to inform their decision to power through upon clear of car traffic.
The point of a roundabout is to eliminate full stops of long duration that would occur at a stop sign or light controlled intersection. They are *not* meant to be frictionless; they only work by the express presence of friction. To think that a driver having to slow down is a problem is to misunderstand roundabouts.
As for why we block out the central portion of a roundabout with a hill/tall grass/artwork, it helps to slow down cars by making it seem like a larger obstacle, and critically it removes non-useful information. When entering a roundabout, we want a driver to look left and right at their crosswalk for pedestrians, and to the left for cars. That's it, period. They should not choose to enter or not enter a roundabout because of what is happening at future exits; by the time they arrive, most happenings will have ended or changed. We especially don't want someone looking straight ahead for the entrance directly opposite them, and missing the goings-on happening at their car, or looking at the exit directly opposite them [when entering], seeing it clear, and then having that information guide them into being less likely to check that information at the critical time [when you've actually gotten to that exit]. It's like a driver looking at a crosswalk when turning left, seeing it empty, then focusing on cars coming at them, and going through when the cars clear, only to screech to a halt for a pedestrian well into their crossing, but one that started after the initial glance that the driver used to inform their decision to power through upon clear of car traffic.
The point of a roundabout is to eliminate full stops of long duration that would occur at a stop sign or light controlled intersection. They are *not* meant to be frictionless; they only work by the express presence of friction. To think that a driver having to slow down is a problem is to misunderstand roundabouts.