Why the fuck would you have right turns on the same signal as straight?
Your parents didn’t even try to educate you, did they?
There are a lot of different kinds of intersections. Simple two-lane meets two lane where each kind has a stop-go light, up to hugely complicated intersections with multiple turn lanes in each direction.
At a small stop-go light, like you might find in a residential neighborhood, there’s one travel lane in all four directions, and each one is a left, straight and right lane. Going left is a yield across oncoming traffic, a green light gives you right of way to go straight or right.
A more medium size intersection might have left and right turn lanes in addition to one or two travel lanes. Let’s say Some Road (N/S) is crossing Another Street (E/W). Some Road is a four-lane divided highway, and at this intersection it has both right and left turn lanes. Another Street is a 2 lane road with much less traffic than Some Road, so it comes out to a left turn lane and a straight/right turn lane.
A typical light cycle will go Some Road gets green circles and green right arrows. Straight lanes bound North and South get to go, as well as those turning right onto Another Street. The through traffic on Some Road blocks any other right of way that could collide with those right turn lanes.
The through lights will turn red, possibly the turn lights will stay green, and the left turn lanes on Another Street will turn green. They can now make a protected left across the intersection, again this blocks any other traffic from colliding with the right turns from Some Road to Another Street, so they retain the right of way.
Finally, those will turn red (or sometimes flashing yellow meaning yield) and Another Street’s straight/right lanes get to go. This cycle will then repeat.
This is for an intersection that doesn’t have sidewalks. You’ll find these out in the middle of nowhere where a state route crosses a federal highway. Interstates and highways built like them will have overpasses and non-blocking intersections.
Where you DO have sidewalks, such as larger intersections inside cities, there are signals for the crosswalks. Those are interlinked with the traffic signals, and depending on the implementation there won’t be any straight and turn signals because “cars go straight” is when the pedestrians cross. When turn lanes are on, all pedestrian traffic is stopped.
Note that these are two different environments; at an intersection in a city center, the speed limits are often 20mph, and frankly, bicycles should not have their own lanes there. By law they’re vehicles, they should be in traffic behaving the same as cars and have the right of way that cars do. Where they get themselves killed is trying to weave in and out of traffic, or insisting on putting in a parallel bike lane pretending it turns off friendly fire. “Just add to every driver’s cognitive load and make them responsible for my safety.” Fuck off.
Meanwhile, back out on Some Road and Another Street, these have 45 and 55 mph speed limits, you’re traveling from town to town here, and these places pretty much should not see bicycle traffic. Here we’re really in the realm of discussing better public transportation and rail service than pedestrian and cycle routes.
Tar_alcaran@sh.itjust.works 13 hours ago
I have a bachelor’s in civil engineering, and that’s part of the reason why I’m able to pierce through the deep coating of carbrain induced status-quo thinking.
You’re making all the wrong assumptions right from the start.
These shouldn’t even exist. A residential neighborhood shouldn’t have traffic lights, and it should have a low enough speed and low enough volume of cars (only the people who live there should be driving there) that accidents should be rare and low risk.
The fact that you assume there’s a traffic light here starts from the basic assumption that there is so much car traffic that it needs managing. You’ve already designed your residential street wrong then.
Skipping this, because these intersections shouldn’t have ANY bicycle interactions at all. If bikes are crossing your 4-lane divided highway, you’ve already designed your roads wrong. I would argue if you’re putting a full streetlevel crossing in, you’re also not doing great unless you get paid per traffic jam.
A protected bike path and protected intersection REDUCE everyone’s mental load because it makes it practically impossible to hit a bike. And it separates bikes from traffic too, so they can’t weave.
The problem with American bike gutters with painted lines is that cars enter them constantly, by design. Cars cross the bike lane to park, they cross it to turn right, and something they just drive in it because the drivers are idiots. Or cars park in it because they’re idiots. And every time a car enters the bike path, the bike needs to move or die. So they move, creating more risks.
All of those problems go away with a raised barrier between the bikes and the cars. You can just stop thinking about them, because they’re in an entirely different lane that you physically can’t even get to. And if you turn right, you can treat them like any other vehicle again, where they’ll have the right of way or there’s a traffic light.
Depends. A 20km bike ride is totally fine, an 80km one isn’t. But if there’s cars going 55mph right next to me, I won’t be taking a bike because that’s super dangerous. There should be a seperate bike path there as well, removing all risks.
Of course, only if it’s actually inhabited in that distance.
captain_aggravated@sh.itjust.works 12 hours ago
There’s a lot of "should"s in there that just don’t reflect reality. Because of how so many American towns and cities are built, you’d have to bulldoze entire cities to do things like eliminate small traffic lights from residential neighborhoods. And we’re not gonna do that. We’re not going to tear down the entire fucking nation for some retards on bicycles.
Tar_alcaran@sh.itjust.works 10 hours ago
Weird how countries manage just fine without bulldozing. What they actually do is switch up road lanes and on-street parking, and it fits just fine.
Having multiple lanes in between level intersections adds pretty much nothing to the capacity anyway, so you may as well use it for something useful.
Terminal carbrain: not realizing that getting more people on bikes means fewer cars, less traffic and a nicer trip for literally everyone, including cars.