Differential speed limits

[Crash_It]

I never said that I was in favor of such limiting devices.

Sorry, I got your replies and Crash_It's replies mixed up.

I can see a company policy limiting the truck to like 68 MPH or something like that. To my way of thinking, if they aren't capable of going 70 MPH (because of company limitation). they shouldn't be in the lane for 70 MPH traffic unless the two trucks involved basically have the road to themselves. I also haven't taken a position on the increase to 65MPH on the truck speed limit in California (on rural roads, presumably where cars can go 70 MPH).

(1)  You seem to consider the speed limit to be a minimum rather than a maximum.  If your vehicle can't go over 70 mph, then there's no reason you shouldn't be allowed in a lane where all traffic is required by law to drive under 70 mph.

Oh really? Is that so? Go drive 55 alongside someone else that's going 55 in a 70 zone with only two lanes per direction and see what happens to you.

[jakeroot]

(1)  You seem to consider the speed limit to be a minimum rather than a maximum.  If your vehicle can't go over 70 mph, then there's no reason you shouldn't be allowed in a lane where all traffic is required by law to drive under 70 mph.

It's not legal in the state of WA for two cars to drive side-by-side at the speed limit. Far left lane is for passing only. If you're not passing, you're impeding traffic, which is against the law.

(2)  Where you live, are there lanes with different speed limits side-by-side?  I've seen that before, but never in the USA.  My opinion of it can be found here.  If, on the other hand, all lanes have the same speed limit, then there's no such thing as "the lane for 70 MPH traffic".  It's just as illegal to drive 71 mph in the left lane as in the right lane, and it's just as legal to drive 69 mph in the left lane as in the right lane.

Many freeways in Seattle have per-lane limits. I-5, I-90, WA-520.

[roadfro]

(2)  Where you live, are there lanes with different speed limits side-by-side?  I've seen that before, but never in the USA.  My opinion of it can be found here.  If, on the other hand, all lanes have the same speed limit, then there's no such thing as "the lane for 70 MPH traffic".  It's just as illegal to drive 71 mph in the left lane as in the right lane, and it's just as legal to drive 69 mph in the left lane as in the right lane.

As re #2: There are several places on I-80 in California in the Sierras where the right lane has a 50 MPH speed limit and the rest of the road is posted at 65 MPH. In California, trucks are only allowed out of the right lane in order to pass and then only in the second right lane. With 4 or more lanes in the same direction, they are allowed only in the right two lanes (unless there is a permissive sign or there is some reason why the must be there, like a left exit or left turn, the right two lanes are exit only, etc). On I-5 (which I think that we can both agree needs a third lane that would fix about 97% of our problems and could be built in the existing right of way), it is too frequent of an occurrence that trucks going 63 or 64 MPH (for which they could currently be ticketed for exceeding the State Maximum 55 MPH for trucks) will block the normal and reasonable flow of traffic for quite a while. Perhaps, if we let trucks go 65 MPH in these places, they either wouldn't feel the need to pass as often or would be passing at a higher speed that would get the move completed in a shorter time. On the other hand, 30-40 tons is a lot of weight to be throwing around at 65 MPH (or faster).

(citation needed)

Where on I-80 in the Sierra Nevada is there a posted speed limit of 50mph in one lane and 65 in the other? I have never seen this... I'm fairly certain I-80 is posted for 65 from the Nevada state line clear to Sacramento if not further (state max 55 for trucks/towing not withstanding).

[michravera]

(2)  Where you live, are there lanes with different speed limits side-by-side?  I've seen that before, but never in the USA.  My opinion of it can be found here.  If, on the other hand, all lanes have the same speed limit, then there's no such thing as "the lane for 70 MPH traffic".  It's just as illegal to drive 71 mph in the left lane as in the right lane, and it's just as legal to drive 69 mph in the left lane as in the right lane.

As re #2: There are several places on I-80 in California in the Sierras where the right lane has a 50 MPH speed limit and the rest of the road is posted at 65 MPH. In California, trucks are only allowed out of the right lane in order to pass and then only in the second right lane. With 4 or more lanes in the same direction, they are allowed only in the right two lanes (unless there is a permissive sign or there is some reason why the must be there, like a left exit or left turn, the right two lanes are exit only, etc). On I-5 (which I think that we can both agree needs a third lane that would fix about 97% of our problems and could be built in the existing right of way), it is too frequent of an occurrence that trucks going 63 or 64 MPH (for which they could currently be ticketed for exceeding the State Maximum 55 MPH for trucks) will block the normal and reasonable flow of traffic for quite a while. Perhaps, if we let trucks go 65 MPH in these places, they either wouldn't feel the need to pass as often or would be passing at a higher speed that would get the move completed in a shorter time. On the other hand, 30-40 tons is a lot of weight to be throwing around at 65 MPH (or faster).

(citation needed)

Where on I-80 in the Sierra Nevada is there a posted speed limit of 50mph in one lane and 65 in the other? I have never seen this... I'm fairly certain I-80 is posted for 65 from the Nevada state line clear to Sacramento if not further (state max 55 for trucks/towing not withstanding).

The citation was fairly easy to obtain from CalTrans and the CVC:
DESIGNATED LANES for VEHICLES with a 55 MPH SPEED LIMIT
Vehicles that are required to travel at a maximum of 55 mph on California highways must use a designated lane or lanes, as stated in the CVC below:

21655. (a) ... (b) Any ... vehicle subject to the provisions of Section 22406 shall be driven in the lane or lanes designated ... whenever signs have been erected... . ..., when a specific lane or lanes have not been so designated, ... those vehicles shall be driven in the right-hand lane for traffic or as close as practicable to the right edge or curb. If, however, a specific lane or lanes have not been designated on a divided highway having four or more clearly marked lanes for traffic in one direction, ... those vehicles may also be driven in the lane to the immediate left of that right-hand lane, ... When overtaking and passing another vehicle proceeding in the same direction, the driver shall use either the designated lane, the lane to the immediate left of the right-hand lane, or the right-hand lane for traffic ... This subdivision does not apply to a driver who is preparing for a left- or right-hand turn or who is entering into or exiting from a highway or to a driver who must ... drive in a lane other than the right-hand lane to continue on his or her intended route.


As to the signs for "THIS LANE/(DOWN ARROW)/(REGULATORY)50(MPH)" on I-80, I have only driven the section twice in the last 5 years. My recollection is that they are on the section in Placer County east of Auburn where the rightmost lane often closes during snow and in the section in which chain controls often exist, so it would be easy to miss during ski season and there are only two or three of them. If I recall, they are often posted in an area where advisory speeds are also posted.

[jakeroot]

^^
That citation of the CVC has nothing to do with roadfro's opposition to your claim of 50mph lanes on I-80.

Your third paragraph, which is the only relevant response, is entirely anecdotal. I'm not saying your BS'ing us, but, well...pics or it didn't happen

[michravera]

^^
That citation of the CVC has nothing to do with roadfro's opposition to your claim of 50mph lanes on I-80.

Your third paragraph, which is the only relevant response, is entirely anecdotal. I'm not saying your BS'ing us, but, well...pics or it didn't happen

roadfro's request for a citation was apparently for where trucks were allowed to drive in California. He simply indicated that he had never seen different speeds posted for different lanes of traffic and I asserted that I had seen them on I-80 and gave my closest approximation to where I had seen them, so that someone else could post documentary evidence, if it suited them to do so. I have no plans to visit that area until the next time the North American Bridge Championships are held in Reno.

But, I can do better than that, there are plenty of FasTrak lanes with special speed limits. As the reader technology improves, those limits will also disappear.

[jakeroot]

roadfro's request for a citation was apparently for where trucks were allowed to drive in California. He simply indicated that he had never seen different speeds posted for different lanes of traffic and I asserted that I had seen them on I-80 and gave my closest approximation to where I had seen them, so that someone else could post documentary evidence, if it suited them to do so. I have no plans to visit that area until the next time the North American Bridge Championships are held in Reno.

Not quite. roadfro was asking for you to prove that a split limit exists for all cars on I-80. Not only did you not mention that the 50-limit and exclusive lane were only for trucks, the post you quoted (by kphoger) was asking about lane-specific limits for all cars, not trucks. Your first response to that post was "There are several places on I-80 in California in the Sierras where the right lane has a 50 MPH speed limit and the rest of the road is posted at 65 MPH" ... this is not wrong, per se, but that 50 limit is for trucks, not cars.

kphoger was asking about limits like this, where (in this example) all cars can go 60 in one lane, but all other cars (in every other lane) must only go 45...lane-based limits for all cars, not just trucks:

[kphoger]

Oh really? Is that so? Go drive 55 alongside someone else that's going 55 in a 70 zone with only two lanes per direction and see what happens to you.

It's not legal in the state of WA for two cars to drive side-by-side at the speed limit. Far left lane is for passing only. If you're not passing, you're impeding traffic, which is against the law.

None of that matters to what I was talking about.

What I had replied to was "To my way of thinking, if they aren't capable of going 70 MPH (because of company limitation). they shouldn't be in the lane for 70 MPH traffic unless the two trucks involved basically have the road to themselves."  What such an assertion means is that a trucker whose rig is limited to 69 mph should not be allowed to pass another trucker going 50 mph.  That's ridiculous.  I've driven on highways with  60- to 70-mph speed limits where heavy-laden turnpike doubles can barely manage 20 mph up the hill.  What would you have all the other trucks do that are able to maintain a good 45 to 50 mph?  Slow down to 15?  Your suggestion solution is intolerable in the real world.

I have a fundamental problem with that setup:  it is illegal to drive at any speed between 45 mph and 60 mph without obstructing the left lane.

[roadfro]

roadfro's request for a citation was apparently for where trucks were allowed to drive in California. He simply indicated that he had never seen different speeds posted for different lanes of traffic and I asserted that I had seen them on I-80 and gave my closest approximation to where I had seen them, so that someone else could post documentary evidence, if it suited them to do so. I have no plans to visit that area until the next time the North American Bridge Championships are held in Reno.

Not quite. roadfro was asking for you to prove that a split limit exists for all cars on I-80. Not only did you not mention that the 50-limit and exclusive lane were only for trucks, the post you quoted (by kphoger) was asking about lane-specific limits for all cars, not trucks. Your first response to that post was "There are several places on I-80 in California in the Sierras where the right lane has a 50 MPH speed limit and the rest of the road is posted at 65 MPH" ... this is not wrong, per se, but that 50 limit is for trucks, not cars.]

Confirming what jakeroot said. I interpreted michravera's statement to assert that there are separate signed speed limits for each lane that apply to all vehicles, for which I requested evidence as that is something I have not seen over the last 17-ish years that I've made occasional trips from Reno to points west via I-80.

And in any case, the typical signed truck speed limit in CA is 55, not 50. There *might* be some curve/truck rollover warning signs marked for 50...

[UCFKnights]

Oh really? Is that so? Go drive 55 alongside someone else that's going 55 in a 70 zone with only two lanes per direction and see what happens to you.

It's not legal in the state of WA for two cars to drive side-by-side at the speed limit. Far left lane is for passing only. If you're not passing, you're impeding traffic, which is against the law.

None of that matters to what I was talking about.

What I had replied to was "To my way of thinking, if they aren't capable of going 70 MPH (because of company limitation). they shouldn't be in the lane for 70 MPH traffic unless the two trucks involved basically have the road to themselves."  What such an assertion means is that a trucker whose rig is limited to 69 mph should not be allowed to pass another trucker going 50 mph.  That's ridiculous.  I've driven on highways with  60- to 70-mph speed limits where heavy-laden turnpike doubles can barely manage 20 mph up the hill.  What would you have all the other trucks do that are able to maintain a good 45 to 50 mph?  Slow down to 15?  Your suggestion solution is intolerable in the real world.

I have a fundamental problem with that setup:  it is illegal to drive at any speed between 45 mph and 60 mph without obstructing the left lane.

Isn't that an express lane where entry is only permitted where marked? So you aren't really allowed to enter the lane with a higher speed limit at that point?

My memory from drivers ed in Florida is that by statute, the minimum speed limit on any road is 15mph slower then the maximum unless otherwise posted. Our highways used to have that posted but its been disappearing as signs get replaced.

[jakeroot]

I have a fundamental problem with that setup:  it is illegal to drive at any speed between 45 mph and 60 mph without obstructing the left lane.

Isn't that an express lane where entry is only permitted where marked? So you aren't really allowed to enter the lane with a higher speed limit at that point?

The left lane is an HOV lane with 24-hour restrictions. But access is unlimited, as it's a single white line. (I-5 northbound, south of Seattle, for the record)

kphoger, was your last sentence meant to be a question? I'm not sure what you're asking or stating.

Basically, the far left lane has a higher limit because the general purpose lanes have slower moving traffic ahead (which in this case, isn't affecting the HOV lane).

[michravera]

roadfro's request for a citation was apparently for where trucks were allowed to drive in California. He simply indicated that he had never seen different speeds posted for different lanes of traffic and I asserted that I had seen them on I-80 and gave my closest approximation to where I had seen them, so that someone else could post documentary evidence, if it suited them to do so. I have no plans to visit that area until the next time the North American Bridge Championships are held in Reno.

Not quite. roadfro was asking for you to prove that a split limit exists for all cars on I-80. Not only did you not mention that the 50-limit and exclusive lane were only for trucks, the post you quoted (by kphoger) was asking about lane-specific limits for all cars, not trucks. Your first response to that post was "There are several places on I-80 in California in the Sierras where the right lane has a 50 MPH speed limit and the rest of the road is posted at 65 MPH" ... this is not wrong, per se, but that 50 limit is for trucks, not cars.]

Confirming what jakeroot said. I interpreted michravera's statement to assert that there are separate signed speed limits for each lane that apply to all vehicles, for which I requested evidence as that is something I have not seen over the last 17-ish years that I've made occasional trips from Reno to points west via I-80.

And in any case, the typical signed truck speed limit in CA is 55, not 50. There *might* be some curve/truck rollover warning signs marked for 50...

The signs, when and where they exist, have (or had) a first line that says "THIS LANE". The second line has (or had) an arrow pointing at the lane, and the bottom part of the sign has (or had) a regulatory (that is to say "black on white") "50" sign. I forget whether it had the "MPH" on it or not. The lane is (or was) not specifically a truck lane, but trucks would have normally driven there, and it is (or was) not a truck only speed limit. And yes, as I recall, the section of road had frequent bends that were advised down to 55 MPH. As I said, these were in lanes that would frequently not be in use during chain controls.

[jeffandnicole]

My memory from drivers ed in Florida is that by statute, the minimum speed limit on any road is 15mph slower then the maximum unless otherwise posted. Our highways used to have that posted but its been disappearing as signs get replaced.

If that's true, that applies solely to Florida.  Other states may have similar rules, but they would always be state specific.

[roadfro]

roadfro's request for a citation was apparently for where trucks were allowed to drive in California. He simply indicated that he had never seen different speeds posted for different lanes of traffic and I asserted that I had seen them on I-80 and gave my closest approximation to where I had seen them, so that someone else could post documentary evidence, if it suited them to do so. I have no plans to visit that area until the next time the North American Bridge Championships are held in Reno.

Not quite. roadfro was asking for you to prove that a split limit exists for all cars on I-80. Not only did you not mention that the 50-limit and exclusive lane were only for trucks, the post you quoted (by kphoger) was asking about lane-specific limits for all cars, not trucks. Your first response to that post was "There are several places on I-80 in California in the Sierras where the right lane has a 50 MPH speed limit and the rest of the road is posted at 65 MPH" ... this is not wrong, per se, but that 50 limit is for trucks, not cars.]

Confirming what jakeroot said. I interpreted michravera's statement to assert that there are separate signed speed limits for each lane that apply to all vehicles, for which I requested evidence as that is something I have not seen over the last 17-ish years that I've made occasional trips from Reno to points west via I-80.

And in any case, the typical signed truck speed limit in CA is 55, not 50. There *might* be some curve/truck rollover warning signs marked for 50...

The signs, when and where they exist, have (or had) a first line that says "THIS LANE". The second line has (or had) an arrow pointing at the lane, and the bottom part of the sign has (or had) a regulatory (that is to say "black on white") "50" sign. I forget whether it had the "MPH" on it or not. The lane is (or was) not specifically a truck lane, but trucks would have normally driven there, and it is (or was) not a truck only speed limit. And yes, as I recall, the section of road had frequent bends that were advised down to 55 MPH. As I said, these were in lanes that would frequently not be in use during chain controls.

I'm 99% certain what you're describing doesn't exist on I-80 in CA, or at least not in regular existence in the last 17 years. I would've remembered something that peculiar.

Legislating a regular lane speed differential like that for all vehicles seems incredibly unsafe to begin with.

[michravera]

roadfro's request for a citation was apparently for where trucks were allowed to drive in California. He simply indicated that he had never seen different speeds posted for different lanes of traffic and I asserted that I had seen them on I-80 and gave my closest approximation to where I had seen them, so that someone else could post documentary evidence, if it suited them to do so. I have no plans to visit that area until the next time the North American Bridge Championships are held in Reno.

Not quite. roadfro was asking for you to prove that a split limit exists for all cars on I-80. Not only did you not mention that the 50-limit and exclusive lane were only for trucks, the post you quoted (by kphoger) was asking about lane-specific limits for all cars, not trucks. Your first response to that post was "There are several places on I-80 in California in the Sierras where the right lane has a 50 MPH speed limit and the rest of the road is posted at 65 MPH" ... this is not wrong, per se, but that 50 limit is for trucks, not cars.]

Confirming what jakeroot said. I interpreted michravera's statement to assert that there are separate signed speed limits for each lane that apply to all vehicles, for which I requested evidence as that is something I have not seen over the last 17-ish years that I've made occasional trips from Reno to points west via I-80.

And in any case, the typical signed truck speed limit in CA is 55, not 50. There *might* be some curve/truck rollover warning signs marked for 50...

The signs, when and where they exist, have (or had) a first line that says "THIS LANE". The second line has (or had) an arrow pointing at the lane, and the bottom part of the sign has (or had) a regulatory (that is to say "black on white") "50" sign. I forget whether it had the "MPH" on it or not. The lane is (or was) not specifically a truck lane, but trucks would have normally driven there, and it is (or was) not a truck only speed limit. And yes, as I recall, the section of road had frequent bends that were advised down to 55 MPH. As I said, these were in lanes that would frequently not be in use during chain controls.

I'm 99% certain what you're describing doesn't exist on I-80 in CA, or at least not in regular existence in the last 17 years. I would've remembered something that peculiar.

Legislating a regular lane speed differential like that for all vehicles seems incredibly unsafe to begin with.

The signs would be easy to miss. They are, if I recall correctly, for only short periods and only on the uphill side, and, if I remember right, only eastbound. They often have a VMS that advises 50 MPH on the westbound side during light snow. VMS would be *THE* way to handle differential speed limits, in my opinion, but these two or three signs are (or were) fixed. As I said, they would be easy to miss. The are only over the right lane and that lane is frequently unused during chain controls.

[kphoger]

I have a fundamental problem with that setup:  it is illegal to drive at any speed between 45 mph and 60 mph without obstructing the left lane.

kphoger, was your last sentence meant to be a question? I'm not sure what you're asking or stating.

My post was a single declarative sentence.

And my fundamental issue remains:  If my vehicle qualifies for the HOV lane and the lanes are divided by only a single white line, then in order to drive 50 mph I am legally obligated to enter the left lane at 10 mph below the limit.

[jeffandnicole]

I have a fundamental problem with that setup:  it is illegal to drive at any speed between 45 mph and 60 mph without obstructing the left lane.

kphoger, was your last sentence meant to be a question? I'm not sure what you're asking or stating.

My post was a single declarative sentence.

And my fundamental issue remains:  If my vehicle qualifies for the HOV lane and the lanes are divided by only a single white line, then in order to drive 50 mph I am legally obligated to enter the left lane at 10 mph below the limit.

No different than entering any roadway from another roadway, especially after a stop or yield sign.

[kphoger]

I don't follow.

[jeffandnicole]

I enter a 55 mph roadway from a stop sign.  I'm doing 0 mph, gaining speed.  Until I'm up to the 'minimum speed limit', I'm breaking the law in your scenario.

[kphoger]

I enter a 55 mph roadway from a stop sign.  I'm doing 0 mph, gaining speed.  Until I'm up to the 'minimum speed limit', I'm breaking the law in your scenario.

OK.  Let me reword it:  it's legal to drive 50 mph on that highway, so people had better be OK with me driving that speed in the left lane.

Or let's reverse things:  before changing lanes out of the left lane, one is legally obligated to slow down to 15 mph below the speed limit first.  I sure hope nobody behind me minds me doing so first!

[jakeroot]

I have a fundamental problem with that setup:  it is illegal to drive at any speed between 45 mph and 60 mph without obstructing the left lane.

kphoger, was your last sentence meant to be a question? I'm not sure what you're asking or stating.

My post was a single declarative sentence.

I cannot read today. I kept reading "is it" instead of "it is".

I enter a 55 mph roadway from a stop sign.  I'm doing 0 mph, gaining speed.  Until I'm up to the 'minimum speed limit', I'm breaking the law in your scenario.

OK.  Let me reword it:  it's legal to drive 50 mph on that highway, so people had better be OK with me driving that speed in the left lane.

In that photo, there are two legal speeds: 60 in the HOV lane, 45 in the general-purpose lanes. Anything in-between is only OK when changing between the two lanes.

Also, driving in the left lane at the speed limit is only OK if you're passing someone. Otherwise, that'll get you pulled over in WA (where the photo is from) (HOV lane does not count as passing lane, for the record).

Or let's reverse things:  before changing lanes out of the left lane, one is legally obligated to slow down to 15 mph below the speed limit first.  I sure hope nobody behind me minds me doing so first!

Since the right lanes only have lower limits during heavier traffic, it's to be expected that you'll need to slow down to merge in anyway. But from a legal standpoint, I suppose you're correct, but no cop is going to enforce that. It's a technicality at best.

[kphoger]

Also, driving in the left lane at the speed limit is only OK if you're passing someone. Otherwise, that'll get you pulled over in WA (where the photo is from) (HOV lane does not count as passing lane, for the record).

What do you mean by "does not count" there?  Do mean that it's OK to be in the left lane without passing someone, so long as the left lane is an HOV lane?  In that case, my point stands:  if my car qualifies as HOV, then I can drive 50 mph in the 60-mph HOV lane.

[jakeroot]

Also, driving in the left lane at the speed limit is only OK if you're passing someone. Otherwise, that'll get you pulled over in WA (where the photo is from) (HOV lane does not count as passing lane, for the record).

What do you mean by "does not count" there?  Do mean that it's OK to be in the left lane without passing someone, so long as the left lane is an HOV lane?  In that case, my point stands:  if my car qualifies as HOV, then I can drive 50 mph in the 60-mph HOV lane.

RCW 46.61.100 governs "keep right laws"....subsection 3 indicates that it does not apply to HOV lanes as they are "not considered the left-hand lane of a roadway".

I think you can drive below the limit, but once five cars are behind you, you have to leave the HOV lane to let them by. Travelling below the limit might still be considered "impeding normal/reasonable movement of traffic".

Honestly, the law isn't very clear on the matter. Common practice in WA is for carpools to use the HOV lane at all times, leaving it when approached from the rear by a faster vehicle (not because they are legally obliged to, but to avoid road-rage). I believe the state patrol has, on several occasions, instructed drivers to do this, to avoid road-rage confrontations.