Other road users

Going up
In the mountains you are climbing on the bike up much slower than other traffic. You will be easily overtaken. The question is how much space you take on the road.
Are you going to ride along the side of the road, you will be seen as nothing more than an object to pass. Car drivers will not cut their speed, or little at best, and do not make a wide berth while passing. You notice that they are not ‘in touch’ with you. If you take up a little more space, a motorist will usually react by reducing speed somewhat, and pass you with more distance. Thus, there is contact. He considers you. And that is safer and more agreeable.

If there is also an vehicle oncoming while another is waiting behind you, that motorist behind you sometimes passes you tightly. You can anticipate on that because as a cyclist, you see or hear the oncoming vehicle earlier.

Signals to traffic from behind
Nothing is more annoying for a driver, for example a slow truck, than having to wait behind two chattering cyclists riding side by side until he can see if he can overtake the two. All the time there will be no oncoming traffic, and when he can oversee the road, there is an oncoming vehicle. So he needs to drive through some curves behind the cyclists until he has clear view on a clear road.
If you are a cyclist you can see earlier that there is room for the driver to pass, so you can give him a signal. He will be grateful for you. You look behind you to let him know “I’ve seen you.” You make contact. One finger, or a hand signal: “Attention, please wait.” And then you gesture “You can now pass.”
Weave when you are riding as a group. Link
See also: Dealing with other roadusers

Going down
In the descent, you often go on the road bike about as fast as motorists.

take up space
You ride downhill not on the side of the road, but as a motorcyclist, you ride more to the middle. Then you have the necessary room to maneuver. It is obvious to a driver that you will use as much space as he. He will keep that in mind.
If you keep too much to the side of the road, then he can even pass in a place where it is not convenient for you. For example, just before the bend.
See also: room to move

Riding more to the middle in a downhill also prevents you from ending up in the often poorer conditions at the side of the road.

Corners: differences between cars and bikes
When cornering, there is a difference between cars (and bikers) and cyclists. Cars can drive on the straights much faster and also brake later, but take the turn much slower. As a cyclist you need less space and if you make the turn somewhat wider by going “outside-inside-outside”, you can ride through the curve faster than a motorist.
See also: taking sharp turns

It’s pretty difficult for you as a cyclist when a  motorist overtakes you just before the curve and then go hard on the brakes. Keep him behind you if possible by riding wide on the road and, if necessary, to give a signal: “Please wait.” Then of course a friendly signal after the turn the call “You can go past”. And a ‘thank you’ thumb-up.

If the road is less steep and your speed goes down you can move to the side the road somewhat more. Possibly you give the traffic behind the call: “Go just past.”

For example, cyclists and cars tractor

 

Cyclists are overtaken. Nice to see that the cyclists keep tightly to the right and other traffic keep to the left where there’s good forward vision. The second part of the road is steep and has more curves. Cyclists are actually faster than the tractor, but it is not safe to overtake. The rider has to brake all the time. In fact, this is a wasted descent! Why not stop and then restart? Then you have a clear way and you can go down pretty hard.

Example: oncoming traffic

Overtaking with (in the distance) another slight turn. As there is no clear view all the way through, but (somewhat) unexpected oncoming traffic when overtaking. Risky? Definitely a bit. The ones who were overtaken help out by driving on the side of the road.
At the end of the bend there’s another oncoming vehicle, but then there’s plenty of room at the right side to get out of the way right away. You must know this or have arranged this!
As for the risk, the wide angle (fisheye) distorts the distances a bit, making it look somewhat riskier than it is. Hearing the mutual signals, you can conclude ther is no panic.

See also: Dealing with other road users