5
votes
What kind of splines should be used when planning roads?
Roads are usually designed using catenary curves. https://sketchup.engineeringtoolbox.com/catenery-curve-c_169.html
Road curves are designed around vehicle velocities and they are not uniform. As ...
- 964
5
votes
What kind of splines should be used when planning roads?
Circular arcs are not used except in special situations, because the sudden change in curvature from a straight road to a circular arc would mean drivers had to quickly turn the steering wheel to the ...
- 12.5k
3
votes
What is the starting/stopping sequence of a traffic light
What country? This is different between different countries.
I can give the sequence in Poland, which is standard in most of EU.
180 seconds of Blinking Yellow. (Groups [**] with Yellow blink ...
- 6,125
3
votes
How do you call the intersection with barrier and you can always right turn?
In UK terminology, your separate turning lane would be called a "filter lane" ( see e.g. Collins dictionary definition). This definition doesn't mean that you can always turn in that lane, it means ...
- 3,135
2
votes
What's the purpose of a 'burger' lane in a roundabout?
Another purpose of such a lane is to allow for vehicles that cannot navigate the roundabout to travel through.
For example a tram's turning radius may not allow them to drive around the roundabout so ...
- 5,751
2
votes
Accepted
What's the purpose of a 'burger' lane in a roundabout?
There are several of these near where I live (in the UK) but I've never heard the term "burger lanes" before. We don't seem to have a name for them - they just are!
They serve the same basic function ...
- 12.5k
2
votes
How do you call the intersection with barrier and you can always right turn?
This is probably an example of a channelized intersection, where you have right turn bays that split from the main road just before the intersection:
References:
Individual Movement Treatments - ...
- 303
1
vote
Accepted
"Burger" lanes: What are they, where are they found, and what do they look like?
if your question is how they look like then:
figure: source hulldailymail
or
figure: source openstreet wiki
They are also known as "through roundabouts"
As to their name I suppose that ...
- 24.3k
1
vote
What kind of splines should be used when planning roads?
Clothoid?
I recall hearing that some roadway curves are designed using the Clothoid Spiral AKA the Spiral of Cornu AKA https://en.wikipedia.org/wiki/Euler_spiral
in which the (radius of) curvature ...
- 161
1
vote
What is the starting/stopping sequence of a traffic light
There is another state the lights can be in: blinking yellow. Which means that the intersection is not being controlled and normal priority rules are in force. Going from off to all blinking does not ...
- 5,751
1
vote
How can traffic signal controllers handle multiple conflicting preemption requests of equal priority without dropping one?
As you might well imagine, there is a metric f-ton (the technical term :-) ) of research covering both queuing theory and prioritization analysis.
The correct, if unsatisfying answer to your ...
- 4,199
1
vote
Historically, how did tram switches work?
I think you don't understand how the switch can work if there is no place to put the lever in the middle of a street. The answer is simple: you only put the socket and every driver brings his own ...
- 426
1
vote
Historically, how did tram switches work?
I don't see why the simplest explanation isn't the best, i.e. manual switches.
Freight trains used to have people on board whose entire job was to manually walk and throw switches. This would work ...
- 10.7k
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