30 to 40 mph in a 65 zone is NOT snails pace!
It’s just you being impatient and trying to speed.
Bullshit.
Wait, what? The OP can go another 25 to 35 mph faster without speeding.
I’ll go along with the theory that the very slow trucks have just got on the highway, and for whatever reason(s)–uphill, heavy loads, a 90 degree turn at the end of the onramp, whatever–just can’t build up speed in that section.
A heavily laden truck either getting up to speed, or grinding up or down an incline, is not slow at 40mph. Where I live the section of freeway next to me is speed limited to 60km/h (35mph) on the downgrade for all trucks. It is enforced too, very seriously. Very heavy trucks will drop to more like 10mph to ensure safety. Nobody complains. The alternative is not good.
Trucks live in a very different regime of power and weight to ordinary folk in cars. Just the nature of the game. No point moaning about it, if you want some of them off the roads build more railways. Lots more.
No he can’t. Prevailing conditions (traffic). The paint on the aluminum doesn’t matter if it’s a blizzard, or zero-visibility rainstorm, or ice, or traffic is moving slower.
The speed limit is whatever is appropriate to the road conditions, up to and including the numbers on the sign… but the numbers on the sign are not a guarantee.
My now-deceased father-in-law was a trucker for many years, and told me how he was often tasked to carry ‘classified top secret’ or very hazardous/sensitive loads from point A to B. He was never told of the cargo on/in trailer but made aware that he would be in prison a long time if he so much as tried to look at cargo that was locked up or tarped excessively from what normal cargo usually has, and was given a device (panic button, per se) that would have all law enforcement available (Feds, too) in a matter of minutes if he pressed the button on it.
He bitched about how many of these loads had a maximum speed of 40-50 mph, apparently due to their sensitivity to bumps or to greatly reduce chance of high-energy wreck, etc. His entire drive-time was monitored by someone somewhere to make sure he did not break the rules of that load. No stopping to use bathroom or deviation from route unless pre-planned (if a great distance was involved) whatsoever unless he wanted to have LEO’s swarming the truck/trailer. Many times with these loads he had to pull whole truck into a secured building and made to wait outside as cargo was off-loaded and cleared from sight. He did do deliveries to place(s) near Area 51 and other high-tech secretive areas, so security/sensitivity of the cargo would be considerable, I bet.
Company he worked for only had a few drivers allowed to make these hauls, so I was told, and he had to go through extensive background check(s), etc as well. Got paid more for these hauls, too, so he did not mind the PIA of going slow and following the rules and getting yelled at/flipper-off by other drivers, fwiw.
He also did a lot of hauls from McAlester Ammo plant in Oklahoma carrying what he assumed were high-explosives or components thereof in trailers that looked like a grocery chain’s trailer or or other innocuous type appearance but I do not know if he had to ‘disappear’ while those offloads happened or whatever. He did say that speed was limited due to the probable explosive/secret/sensitive-to-jolting nature of what he was hauling and sometimes had unmarked State Troopers and other unknown agency cars alternately following him or being nearby the whole route in case of hijack attempt, etc. He even said that on one trip he could see a military-type helicopter not too far away more often than not, like heli was trying not be real obvious but moments away if called upon. Kinda eerie sounding to drive such a load.
There may be a reason similar to above type situations that truck(s) are going so slow in their route. Just saying. But uphill inclines with max-load is more likely, I bet.
An answer I don’t see above is ‘fuel economy.’ There are two ways to drive a vehicle like a semi - constant speed or constant throttle. I don’t know how newer big-diesel technology might have changed this picture, but my guess is “not much” or that old habits persist. (Among truckers? Ya gotta be kidding…)
There are various theories about best economics. One says that if you hold the same speed, you get certain time-over-distance-over fuel advantages. The other emphasizes fuel economy and says that if you keep the same throttle setting for long stretches, you’ll save money and fuel at the expense of almost continuously varying road speed.
Here in the rolling hills of Nwingland, we see both, and there are plenty of slow-up-the-hills, bat-outta-hell-downslope trucks who I assume are following the constant-throttle model. I see plenty of ordinary cargoes on these trucks - beams, heavy equipment, construction materials - so the “special handling” etc. stuff doesn’t seem to be a factor for them.
This drove us insane crossing the country. On the long, rolling hills of the midwest, we spent whole days with trucks that would slow to 35 on the upgrades and we’d have to pass them… only to have them blow past at 90 or more on the downhills. Over and over and over again, for hundreds of miles. (I was limited in top speed by a rooftop cargo carrier, so I couldn’t just floor it and get the hell away from them.)
In which province of which country on which continent do these two numbered roads happen to be? 
Remember: we not only can’t read your mind but we may live on the far side of Earth from you.
Fuel economy or constant-throttle have nothing to do with it. Going uphill the truck is full-throttle but in a lower gear just to get up the hill. Downhill is often no throttle at all depending on the grade. Steeper downhills can also require a lower gear (and slower speed to prevent overspeeding the engine) to allow the engine to reduce the braking required. Long-term or hard braking going down a steep hill overheats the brakes and makes them ineffective. This is why there are runaway truck ramps on steep hills.
As Francis Vaughan said, a fully-loaded truck handles nothing like a car. It’s hard to appreciate if you’ve never driven one.
Okay. The rig drivers I’ve talked to must have been hiding the truth, then. I’ve sat around the fringes of a couple of animated arguments about constant-throttle driving - among long-haul drivers. I have absolutely no judgment of the validity or where the topic might be now, but about 8-9 years ago it was worth pounding the table over for these guys.
Most truck drivers that I dealt with regarded the throttle as an on/off switch.
But these were the days of where the top speed of most trucks was around 70 mph or so
Well, okay, not literally.
They may have been talking about it for flat ground, not for hills.
I see fresh wheel marks on the I-26 runaway ramps quite regularly - I consider those the Zen gardens of the mountainous interstate highways.
nitpick- diesels don’t have a throttle.
Nittierpick - some do
I meant the accelerator pedal:smack: but before the days of electronic fuel injection, the trucks had an manual throttle to bring up the idle when required as we were running various PTO’s off the engine.
Riverside, California, United States of America, North America, Earth
OP - remember, anything with a trailer is limited to the two right lanes, so the slowest of the slow are blocking the right lane and whichever trucks are able to climb that grade at 1mph faster than that are in the right lane blocking everyone else. That hill doesn’t feel like anything in a car but it’s formidable in a 80,000lb rig. (I used to regularly pull maxed out 48’ reefers up it in junky Intertrashional daycabs)
Aye. Pretty sure it’s the only place in the U.S. those 2 freeways intersect. You can assume we’re talking about the U.S. unless otherwise stated.
Sounds like Riverside CA, USA to me…