Variable speed limits (VSL) continue to be experimented with and at times are confusing to human drivers, meanwhile self-driving cars will readily accommodate VSL.
This can be difficult to do.
The hate part of the speed limits usually arises when you are late to work or otherwise in a hurry. At that point, you might carp that the speed limit is too low, even in a peaceful community setting. For sure you are going to be upset about the speed limit on a freeway or open highway. That seems downright stupid as a place to put constraining bounds on the allowed speeds, or at least we ought to make the speed limit high enough that people can travel at “expedient” rates.
There is also the belief that you won’t get a ticket unless you are going at least 5 to maybe 10 miles per hour faster than the posted speed limit. Thus, the sign that says 35 mph is really telling you that you can go 40 to 45 mph, fully legally so. Sorry to burst your bubble but that’s not how speed limits work. You can readily get a ticket for going even a rudimentary one mph over the speed limit.
Another example of speeds that are somewhat changing includes construction zones. You drive toward a roadway construction crew and they might be holding up signs that adjust the normal speed limit in that vicinity. There are also often electronic speed limit signboards that are hauled around by construction teams and put in place to blink repeatedly about the temporary speed limit wherever they are placed.
A static speed limit would not normally allow for that kind of flexibility, while a variable speed limit would.You are driving along and the posted speed limit is shown on an electronic display. Let’s assume it is morning and the roadway is jampacked with cars. Perhaps the display is showing a speed of 35 mph as the speed limit. During your lunch break, you get back onto the roadway and you then observe that the speed limit sign now says 50 mph.
It is easy to point fingers at the faster-moving driver. The dolt should have been looking for the variable speed limit and adjusted accordingly. You are hard-pressed to point a finger at the slower moving driver since they were obeying the posted VSL, though you can likely anticipate that the faster moving driver would try to contend that the slower moving driver was the problem .
You can hear the surprised and dismayed speeding ticket holders insisting that they had never seen such signage before. They assumed that the signage was a practical joke or possibly intended for some purpose other than regulating the speed.The research on this topic is still being conducted and the results of using VSL are typically mushy. VSL admittedly might be overly challenging for humans.
Meanwhile, the Level 4 efforts are gradually trying to get some traction by undergoing very narrow and selective public roadway trials, though there is controversy over whether this testing should be allowed per se . With that clarification, you can envision that the AI driving system doesn’t natively somehow “know” about variable speed limits. This is an aspect that needs to be programmed as part of the hardware and software of the self-driving car.First, the AI driving system has to become aware of the speed limit in whichever locale it is driving. This is usually done by pre-mapping the area that will be traveled by the self-driving car.