VA: Bill allowing 70 MPH passes GA, goes to Gov for signature

[njroadhorse]

I think even I-85 from US 460 south to the NC state line could handle 70 MPH limits, and definitely I-95 south of I-295 to NC.

[74/171FAN]

I think even I-85 from US 460 south to the NC state line could handle 70 MPH limits, and definitely I-95 south of I-295 to NC.

The I-85 portion has been 70 for at least two-three years now.

[Bryant5493]

I think that I-16 east of Macon and west of the Chatham County line could be posted at 75 or 80. 70's too slow for that road -- there's nothing out there, really. Additionally, I feel I-85 south of Newnan could be posted at 75 or 80 as well. Not a lot down near LaGrange and West Point, but Lake West Point and the Kia Plant.

This is a good step in the right direction, posting higher speed limits where prudent.


Be well,

Bryant

[agentsteel53]

a lot of roads would remain safe with speed limits of 80, 85, 90, even 95 or 100 mph.

for those extra-high speed limits I am thinking of western rural routes like I-94 in Montana, I-10 in Arizona, etc.  But even for I-16 in Georgia I would agree with 80mph.  The current speed limits we have in the US are ridiculously low - the roads were built for much higher speed limits (the curves on I-55 in Illinois between Chicago and Springfield are all rated 100-110mph, for example) and driving fast has little do with driving dangerously - it just happens to be an easy law for the lazy to enforce, so it is enforced hard.

drive 95 down a straight section of a little-used road?  get a speeding ticket.  do 60 weaving in and out of rush-hour traffic, on occasion use the median and even the opposite lanes of traffic?  get away with it.

[froggie]

The current speed limits we have in the US are ridiculously low - the roads were built for much higher speed limits (the curves on I-55 in Illinois between Chicago and Springfield are all rated 100-110mph, for example) and driving fast has little do with driving dangerously - it just happens to be an easy law for the lazy to enforce, so it is enforced hard.

Do you have anything to verify this?  Every design plan/document I've seen, for several states, notes a 70 MPH design speed.  Which, BTW, takes more than just curves into account.

[J N Winkler]

for those extra-high speed limits I am thinking of western rural routes like I-94 in Montana, I-10 in Arizona, etc.  But even for I-16 in Georgia I would agree with 80mph.  The current speed limits we have in the US are ridiculously low - the roads were built for much higher speed limits (the curves on I-55 in Illinois between Chicago and Springfield are all rated 100-110mph, for example) and driving fast has little do with driving dangerously - it just happens to be an easy law for the lazy to enforce, so it is enforced hard.

Nope, sorry, won't work, for three reasons:

*  Joints

*  The "dead dog" rule

*  C is too high

In the caes of freeways, rather than speed limits of 100 MPH or more, I would favor derestriction combined with the posting of advisory maximum speeds and (for the benefit of drivers wishing to go faster than the advised maximum) certain relevant geometric parameters.  For example, you might see a black-on-yellow sign (format similar to a speed limit sign) reading "ADVISED MAXIMUM 70," followed by a black-on-yellow sign reading "04-23-70-1000" (translation:  4% maximum superelevation, side friction demand no greater than 23% of gravitational acceleration at 70 MPH for curves on this section, 1000' clear forward sight distance).

[agentsteel53]

I unfortunately do not know what those three points are.

what is a joint, a dead dog, or C? (other than the speed of light, which would be an amazingly badass speed limit)

[agentsteel53]

Do you have anything to verify this?  Every design plan/document I've seen, for several states, notes a 70 MPH design speed.  Which, BTW, takes more than just curves into account.

I do not remember where I read that about I-55; it was many years ago - just one of those facts that sticks with you.

[J N Winkler]

what is a joint, a dead dog, or C? (other than the speed of light, which would be an amazingly badass speed limit)

Joints are gaps in the pavement or bridge deck which are provided to accommodate thermal expansion.  On curves they can lead to brief failures of tire adhesion which in turn result in out-of-control skids if the side friction demand is less than the coefficient of static friction but greater than the coefficient of sliding friction.  This is what kills teenage daredevils who take 45 MPH flyover ramps at 70 MPH or faster.

The "dead dog" rule refers to the derivation of our standards for vertical curvature.  They are based on the assumption that a person cruising at the design speed should be able to see a dead dog in the road ahead in enough time to stop for it, given certain assumptions about reaction time and braking efficiency.  Since assumed driver eye height is fairly high in the US, and the dead dog means that assumed object height is a few inches above the ground rather than right at the road surface, this means our standards for vertical alignment are unconservative.  That in turn affects drivers' ability to see hazards in the road in plenty of time to react when they are cruising significantly faster than the design speed, which is what a suggestion of 100+ MPH limits amounts to.

C in this instance is not the speed of light, but rather the rate of change in lateral acceleration as a vehicle enters a curve.  The value of C (which has traditionally had units of ft/sec³) at the design speed determines the length of the transitions leading into and out of a curve.  C = 1 ft/sec³ is a fairly conservative standard, used in Britain for many years, but we use C = 2 ft/sec³, which results in shorter transitions which are easier to set out in the field.  These are values as measured at the design speed.

Values of C greater than 10 ft/sec³ are considered unsafe.  (Think of someone in an old Model T Ford driving forward while wildly slewing the steering wheel back and forth so that only two wheels are on the ground at any given time--that is what high C looks like.)

If you drive through a curve significantly faster than its design speed, the C you experience will be significantly greater than the design value.  This is because the transition to full superelevation has to occur within the same length but the side friction demand has to reach a higher value and it has to reach that higher value within a shorter period of time.  If the curve has a radius close to the minimum specified for the design speed, there is little slack in the design and C can easily jump to a very high value.  If you are not prepared to supply steering input quickly and smoothly, you could easily skid even with an entry speed well within the performance envelope defined by the car and its tires.  Very fast driving is therefore white-knuckle driving.

As a general rule of thumb, I do not support speed limits significantly above the design speed (which, to my knowledge, has never been more than 70 MPH for a rural Interstate) because in this country our standards for horizontal and vertical curvature are significantly more relaxed than those used elsewhere and we have no tradition of using perspective evaluation to optimize alignments for consistency.  We are not as bad as the Italians in the 1920's, but we belong firmly in the long-tangent, short-curve camp.  Speed enforcement does not deserve to be elevated to the status of a fetish anywhere, including in the US, but because of the geometric characteristics of our Interstates, a focus on it is more nearly in the public interest than in, say, the UK or Germany.

Even if we abolished speed limits on freeways of a certain high quality, there would still be a public interest in regulating speed.  The advantage to posting advisory maximum speeds and certain parameters of road geometry is that it devolves the choice of a safe cruising speed onto the driver, who (assuming weather and traffic are not ruling constraints) can then choose a speed which matches his or her comfort level and the performance characteristics of his or her vehicle.  It would still be necessary to have a legal presumption that the duty to drive defensively weighs more heavily with each increment above the advised maximum.

[agentsteel53]

thanks for the answers!

Even if we abolished speed limits on freeways of a certain high quality, there would still be a public interest in regulating speed.  

I think the public's interest is in regulating safety, and to me (or to you, as noted in the next paragraph) that does not involve absolute speed limits.  

The advantage to posting advisory maximum speeds and certain parameters of road geometry is that it devolves the choice of a safe cruising speed onto the driver, who (assuming weather and traffic are not ruling constraints) can then choose a speed which matches his or her comfort level and the performance characteristics of his or her vehicle.  It would still be necessary to have a legal presumption that the duty to drive defensively weighs more heavily with each increment above the advised maximum.

this sounds like something that Germany does... there is an advisory speed, and if you are traveling faster than that and get in an accident, that fact is taken into account when determining fault, for the purposes of issuing a citation and for the insurance companies.

I would really love to have absolutely no speed limit out in the open.  The closest I've come to that is in Utah, where I believed that the highway patrol would not be anywhere near state route 21, which has absolutely nothing on it for 83 miles between Milford and Garrison.  It makes the Loneliest Road (US-50 in Nevada) look like downtown Los Angeles.  I chose for myself a speed I thought safe and reasonable given the road conditions (sunny day, driving west in morning, no traffic) and my rental car's handling qualities (a midsize Chevy; I forget which one - Malibu?), and set the cruise control.  

My safe and confortable speed was was 104mph.  Nobody harmed, even though the posted limit was 65.  Saw two cars come the other way, didn't pass anyone going my way.  And, as surmised, no highway patrol anywhere.

[mightyace]

driving fast has little do with driving dangerously - it just happens to be an easy law for the lazy to enforce, so it is enforced hard.

Also, in this era of heavy lawyering, it is much easier to enforce than "reckless driving."

To get a speeding conviction, you simply have to show that your objective measurement of the speed of the alleged violator is correct.

"Reckless driving" and other similar offenses (distracted driving) are a subjective judgment of the arresting officer and, hence, easier to question in court.

So once again, thank the lawyers!  

[agentsteel53]

oh, I thank the lawyers every day, and I thank the legislators that have perverted the constitution and forbidden the judicial branch to be in favor of common sense.

back in the day, cases that were deemed to be full of idiocy were promptly dismissed.  Now they are accepted. 

Can you imagine "Mcdonalds Coffee Lady" in 1818?  I bet you can't.

[mightyace]

oh, I thank the lawyers every day, and I thank the legislators that have perverted the constitution and forbidden the judicial branch to be in favor of common sense.

I agree totally.  And, what are most legislators? (at least at the federal level)

LAWYERS! 

[agentsteel53]

I agree totally.  And, what are most legislators? (at least at the federal level)

LAWYERS!  

remember when serving in government was not a permanent sinecure?  Martin Van Buren was president, and after that he was a senator, never taking either position for granted.  Now we get folks like Ted Kennedy who think their position is theirs for life. regardless of how many people they drown.

[Chris]

At least they take the effort of pulling you over. On a per-capita basis, I don't think the U.S. has as many speed cameras as in Europe. I've read somewhere there are 5000 speed cameras on 308 million people. The Netherlands has 1500 speed cameras on only 16 million people...

NL has 94 speed cameras per 1 million
US has 16 speed cameras per 1 million*

* if the figure of 5,000 is correct.

[rawmustard]

At least they take the effort of pulling you over. On a per-capita basis, I don't think the U.S. has as many speed cameras as in Europe. I've read somewhere there are 5000 speed cameras on 308 million people. The Netherlands has 1500 speed cameras on only 16 million people...

NL has 94 speed cameras per 1 million
US has 16 speed cameras per 1 million*

* if the figure of 5,000 is correct.

You can credit that with plenty of states' laws which require that a law enforcement officer personally observe a violation in order for a citation to be issued. Even in states where speed or red-light cameras are permitted, there are still plenty of restrictions on how they are implemented. (For example, in Illinois, speed cameras are only permitted in construction zones.)

[74/171FAN]

I saw the first sign of I-295 becoming 70 on Thursday when I saw two covered-up "Speed Limit XX Ahead" signs with a "Speed Limit 65" sign just beyond it.

[WillWeaverRVA]

I saw the first sign of I-295 becoming 70 on Thursday when I saw two covered-up "Speed Limit XX Ahead" signs with a "Speed Limit 65" sign just beyond it.

Which part of I-295 was this?

[froggie]

Based on VDOT's phasing plan, it'd be the section between I-64 West and US 1.

[74/171FAN]

I saw the first sign of I-295 becoming 70 on Thursday when I saw two covered-up "Speed Limit XX Ahead" signs with a "Speed Limit 65" sign just beyond it.

Which part of I-295 was this?

Based on VDOT's phasing plan, it'd be the section between I-64 West and US 1.

Actually it was SB just before the southern I-95 interchange

[NJRoadfan]

I saw the first sign of I-295 becoming 70 on Thursday when I saw two covered-up "Speed Limit XX Ahead" signs with a "Speed Limit 65" sign just beyond it.

All the speed limit signs on this section now have temporary "65" panels covering "70" from what I saw last Sunday driving though there.

[vdeane]

If the DOT has approved 70mph for that section, and the law allows it, why are the signs covered up?  What's the hold-up?

[74/171FAN]

If the DOT has approved 70mph for that section, and the law allows it, why are the signs covered up?  What's the hold-up?

Because the law doesn't come into effect until July 1 like most Virginia laws

[vdeane]

Well that's silly.  Laws should go into effect immediately unless there's a very good reason not to.

[agentsteel53]

Well that's silly.  Laws should go into effect immediately unless there's a very good reason not to.

I think the "very good reason" in this law is the fact that they do need a bit of time to change the signs from 65 to 70 (with temporary covers to be all taken down on a single early morning).

Looks like the contractors did it more efficiently than the legislature thought they would. 

The law should've certainly taken this into account, and have been written to say "July 1st at the latest; earlier if the contractor finishes the job early".