Originally Posted by Lumatic
There are 2 forces at work it seems. First the bow wave that pushes you away from the passing vehicle. This is immediately followed by a reduction in pressure which sucks you towards it. You get a double whammy when the trailer is hit by the same.
Keep a weather eye on your mirrors for large overtaking vehicles, pull to the right as far as possible, ease up the gas and cover the brake. There is a tendency to over correct steering setting up a dangerous reciprocating sway.
IMHO the worst vehicles seem to be car carriers.
I would like to modify parts of the above. Defensiveness is not timidity (that's how it is interpreted while on the road; and, as this is America, to be taken advantage of: "I'm driving faster so they should move over for me"), and the passing vehicle DOES NOT have right of way over the vehicle being passed. In fact ALL obligation is upon them, for practical purposes. (Speeders have no defense, here).
1] It is your lane (speaking here of the Interstate), so stay centered in it.
Others have a tendency to move towards
a vehicle that is in the right of it's own lane. Dumbo Americano. They nearly none of them know where the right side of their vehicle is, so they tend to ALWAYS maintain the same distance to that side. You move over and they follow. (Don't believe me, then try it out).
I tend to move the rig towards the left lane, and then move back just a bit past center towards the shoulder when the other vehicle is almost on top of me.
I give the other a psychological "push" in other words. This works well whether I'm solo, towing a trailer or driving a tractor-trailer. I maximize the distance
at the right moment, but DO NOT give up the center of my lane to do so. These aren't big movements, but adjustments of lane position. They work. I am riding across the big truck rut trough
from one wave top to the other wave top is about what it amounts to (for you water skiers). Just enough that the usual morons adjust their
position in the passing lane.
We're dancing . . . and I'm taking the lead.
(If I'm worried about someone coming up I may in fact wander all over the lane and literally over into his before they're next to me . . sobers them up quickly I notice: get around that crazy driver!!
One needs all of the room of his lane that he can have. And only from the center of his lane can he be sure of this space; sacred space in a manner of speaking as travel trailer rigs are so very limited in handling.
Do not let others intrude . . push 'em over (don't have the brainless anywhere near you, for any length of time).
The passing vehicle tends to have chosen a path past the slower vehicle a fair distance back, usually unconciously. I want him over in his lane as far as he'll go,
The decent ones out there will already be over a little and well above 5-mph more than my speed. Those who are barely passing or who are sorta passing (on cruise control), and those who travel in the cretin packs bumper-to-bumper with others are not the decent sort!
2] I would also NOT ease up on the throttle, but set the speed -- with positive forward momentum at all times
-- to one that is lower; a bit. Come off the cruise, perhaps, but have NO slack in the rigging (no deceleration occurring) when any other vehicle is near. In fact, if I am worried over who or what is passing I may in fact be accelerating
as they pass me. Not much, and not enough to cancel the speed difference between us, but enough that it is more difficult for the passing bow wave (or waves) to affect momentum.
(For the occasional speed limited big truck barely getting around me, I just drop off the cruise and let him get past then get back over, wait till there's proper distance and glide back up to my travel speed, re-setting the cruise. Never stay near a big truck no matter who is passing. And, big trucks never want to stay in the passing lane!!
Do what you can to shorten that time for them).
Again, this is all rather gentle in effect. My passenger may not notice and my conversation may not flag, it's pretty well automatic. I am only re-setting my steady state to one slightly different (but I've also been doing these things for nearly forty years).
When it is not gentle then I will in fact be moving as far over as possible and down to below 50-mph -- and re-accelerating somewhat -- for the truly scary once-a-decade stuff (a trio of tractor trailers at above 100 mph; never forgot that one .. was all the way onto the shoulder for that).
3] The brake to cover is the brake controller, not the TV service brake. If the rig starts to sway then slam the trailer brake home and slam the TV throttle down at the same time. It's not easy to lock the trailer brakes so that the TT tires slide, but anything
to slow the trailer back to the speed the TV is traveling
is key. (And this is why one wants positive
forward momentum: so that the steering slack is already taken up . . that trailer is going to jerk and jerk hard once the brakes hit.) This is where steering over-correction will occur.
A swaying trailer is trying to pass you. You might reconsider that cutesy name so many are fond of giving theirs as it tries to jerk the TV drive axle loose from it's grip to yank you both into the ditch while at a highway speed.
Do what you can to avoid getting to that point. As was drilled into me, "There's no such thing as an accident".
Wherever the margin to improve your rig can be found, incorporate it. A few $$ will mean a lot in worsening situations of road, load, traffic and weather.
And a fair amount of this is moot for those with either crappy hitch rigging or no WDH. It'll be enough work to keep the danged thing straight in the same crosswind that day. Forget the forms of signaling to others as above.
The best hitched rigs can
have more than just sway elimination going for them . . same for best brakes, best brake controller, best tires at best pressure, etc, etc, et. al. Those little movements of offense are the best defense, IMO. Get the maximum distance and the minimum times.
As to car carriers ("parking lots") the worst possible fuel mileage for any big truck is that type with a 3/4 bow wind off either side. Empty or loaded they are aero nightmares and in having one pass we experience in miniature the reversing wind phenomenon spoken of above and elsewhere usually associated with several trucks.