Just curious ... you find yourself in the right hand lane stuck behind a car doing less than the speed limit.
You signal left / look at the same time as you stated, which is when you see a tractor trailer truck coming up fast in the lane that you're intending to move into.
Do you ;
A. Say a hail mary and go for it. Let's find out how good his brakes are
B. Wait for him to pass, leaving your directional blink, 20, 25, 30 times before he clears and you slide over
C. Shut your directional off and wait for a more opportune time to change lanes, pondering why you didn't just look in the first place
So many variables that would lead to choosing A or B or C depending on those variables.
A. Depends on what car I am in and whether or not I believe I can merge without impacting the truck in that lane. Sometimes I can punch it and have very little impact and sometimes I won't be able to so I don't merge at that time.
B. If it's heavy traffic and I am just merging onto the highway and that is the reason I am stuck behind the car doing less than the speed limit I will likely leave the signal on because I will have to merge eventually and the heavy traffic will require my signal (unless I am in Los Angeles where a signal means speed up in the other lane to not allow me to merge).
C. If I see that it's only the truck and I have a clear space easily behind him then I will turn off the signal and wait for the truck to pass and then merge safely after that. No need to keep the signal on for that long and confuse the truck. Better to just let him continue on his pace and easily merge once he barrels on by at his high rate of speed.
Not an on-ramp scenario. These variables that you are adding seems like an attempt to help your argument.
Let's make it crystal clear then;
A. Your actions will certainly cause the truck to have to brake HARD. Even if he doesn't hit you, he might get rear ended. Tires will skid, horns will be blown.
B. You just got on the highway, merged, and are now traveling for a bit in the right hand lane. The person in front of you that you merged behind is driving slow.
You signaled and looked at the same time to then see the truck bearing down in that outside lane that you want to be in.
C. Yes, the correct answer is C. Turn off your directional and wait until the truck passes.
So if the correct answer is "C", .... then why would you not look first, to see if a lane change is doable, before putting your directional on?
Wouldn't it make more sense to see the truck, wait for it to pass, THEN signal and make your lane change?
I don't care what drivers-ed teaches. Be aware and know your situation before you take any action (or "suggest" to other drivers that you are about to take action).