Night Speed Limits

[silverback1065]

I recently saw in a sign book a special night speed limit sign, it was all black with white lettering saying "night xxx" (the x's below night being the speed limit number) are these in use today?  If so where?  I've never seen them before.

[corco]

All non-interstate state highways in Montana (70/65 night, 60/55 truck night), some of the unlit streets in Tucson AZ for starters

[wxfree]

They were in use in Texas until 2011 almost everywhere the speed limit was above 65.  The statutory default speed limit was 70 and 65 at night, with higher limits applying only during daytime.  In 2011 all Texas night speed limits were banned by statute.  Wikipedia has a photo of a sign arrangement that was very common until a few years ago, showing the default speed limit of 70 and 65 at night.
http://en.wikipedia.org/wiki/File:Texas_speed_limit_70_65.JPG

The only place I know of that has night speed limits now is Wichita Mountains National Wildlife Refuge, where the speed limit is 45/night 35 due to open range conditions and wildlife frequently occupying the roadway.
http://goo.gl/maps/MvtgD

[oscar]

US 550 has reduced night speed limits, in an area with frequent wildlife crossings south of Montrose CO.

[Truvelo]

I'm in two minds about night limits as on the one hand it's dark but on the other there's less traffic around so you should be able to floor it.

[1995hoo]

I believe the Overseas Highway has a night speed limit through the key deer habitat.

[jeffandnicole]

I'm in two minds about night limits as on the one hand it's dark but on the other there's less traffic around so you should be able to floor it.

Then you clearly forgot the part in Drivers Ed that states you should never drive faster than what your headlights permit you to see. The overall driving guideline is that you should drive slower at night, not faster.

[TEG24601]

With modern vehicles and their ability to cast light, especially with high beams, Night Speed Limits are a poor idea, just like Truck Speed Limits.

[1995hoo]

With modern vehicles and their ability to cast light, especially with high beams, Night Speed Limits are a poor idea, just like Truck Speed Limits.

Have you ever driven in heavily wooded areas with large deer populations? Deer running suddenly into the road are a very good reason for lower night speed limits in some places. Not everywhere, mind you, and I'd certainly agree with your statement if you'd phrased it in terms of blanket night speed limits being unnecessary. But particular circumstances can and do make them appropriate in some places.

[KEK Inc.]

The far west states never had them. 


iPhone

[triplemultiplex]

I would bet one reason night SL's have gone away is because who gets to say when "day" ends and "night" begins?  Sunset?  A set time after sunset? Same for sunrise?  What if it's cloudy and you can't tell where the sun is?  What if there's a mountain that blocks the sun in one place but doesn't in another?

These questions would matter if someone is going to try and write a speeding ticket for violating a nighttime SL.

[oscar]

I would bet one reason night SL's have gone away is because who gets to say when "day" ends and "night" begins?  Sunset?  A set time after sunset? Same for sunrise?  What if it's cloudy and you can't tell where the sun is?  What if there's a mountain that blocks the sun in one place but doesn't in another?

These questions would matter if someone is going to try and write a speeding ticket for violating a nighttime SL.

The ones I saw on US 550 south of Montrose CO specify that the 55mph night limit applies 5pm-7am from September to May (the day limit is 60mph). Not sure what happens the other three months, like July when I was there, though obviously "night" is shorter.

[The High Plains Traveler]

The far west states never had them. 
iPhone

Utah did prior to 1974. They used the signs with the first digit having a non-reflective daytime number and a retroreflective nighttime number behind it, so your headlights would reflect the nighttime speed.

The ones I saw on US 550 south of Montrose CO specify that the 55mph night limit applies 5pm-7am from September to May (the day limit is 60mph). Not sure what happens the other three months, like July when I was there, though obviously "night" is shorter.

There were more of those nighttime, wildlife zone limits in the mountains. Most were west of the Continental Divide, but one was on U.S. 24 north of Buena Vista. They were only in effect during the fall and winter months. I think CDOT has done away with them, though, because they were not effective.

[Scott5114]

I would bet one reason night SL's have gone away is because who gets to say when "day" ends and "night" begins?  Sunset?  A set time after sunset? Same for sunrise?  What if it's cloudy and you can't tell where the sun is?  What if there's a mountain that blocks the sun in one place but doesn't in another?

These questions would matter if someone is going to try and write a speeding ticket for violating a nighttime SL.

This is exactly the situation I found myself in when I got my first speeding ticket, in Wheeler County, TX. The sun was mostly down but it was still light out.

If you're gonna have a night speed limit, why not have a rain one too? Or an ice one?

I never really understood why NCUTCD thought having a black sign convey information only applicable at night was such a good idea, either.

[MASTERNC]

Saw them in Jackson Hole, WY where there were a lot of elk. Had one enter the road on the other side as we were driving at night, so I think the night speed limits are reasonable in that situation.

[corco]

With modern vehicles and their ability to cast light, especially with high beams, Night Speed Limits are a poor idea, just like Truck Speed Limits.

Have you ever driven in heavily wooded areas with large deer populations? Deer running suddenly into the road are a very good reason for lower night speed limits in some places. Not everywhere, mind you, and I'd certainly agree with your statement if you'd phrased it in terms of blanket night speed limits being unnecessary. But particular circumstances can and do make them appropriate in some places.

I'd say in a state like Montana, where 95% of rural two lane roads have 70 MPH/65 night speed limits, the night limit is appropriate. So much of the reason that those 70 MPH speed limits are safe and could probably even be considerably faster is because Montana is Big Sky Country, and sight lines are generally significantly further (usually >1/2 mile) than even modern high beams can shine. I get claustrophobic when I drive out east (or in the pacific northwest)- I find your 50/55 MPH speed limits on two lane roads fast because the visibility is so limited compared to what I am used to.

The wildlife argument holds water out here too, even outside of wooded areas. Deer blend in very well with brush, and tend to hang out in the middle of the road at night for some reason.

[dfwmapper]

I would bet one reason night SL's have gone away is because who gets to say when "day" ends and "night" begins?  Sunset?  A set time after sunset? Same for sunrise?  What if it's cloudy and you can't tell where the sun is?  What if there's a mountain that blocks the sun in one place but doesn't in another?

These questions would matter if someone is going to try and write a speeding ticket for violating a nighttime SL.

In Texas, it's defined in state transportation code.
http://www.statutes.legis.state.tx.us/Docs/TN/htm/TN.541.htm

Sec. 541.401. MISCELLANEOUS TERMS. In this subtitle:

(1) "Daytime" means the period beginning one-half hour before sunrise and ending one-half hour after sunset.
(5) "Nighttime" means the period beginning one-half hour after sunset and ending one-half hour before sunrise.

Presumably based on the official sunrise/sunset times.

[KEK Inc.]

The far west states never had them. 
iPhone

Utah did prior to 1974. They used the signs with the first digit having a non-reflective daytime number and a retroreflective nighttime number behind it, so your headlights would reflect the nighttime speed.

The ones I saw on US 550 south of Montrose CO specify that the 55mph night limit applies 5pm-7am from September to May (the day limit is 60mph). Not sure what happens the other three months, like July when I was there, though obviously "night" is shorter.

There were more of those nighttime, wildlife zone limits in the mountains. Most were west of the Continental Divide, but one was on U.S. 24 north of Buena Vista. They were only in effect during the fall and winter months. I think CDOT has done away with them, though, because they were not effective.

Utah isn't far west.  I'm talking about Washington, Oregon and California.  Idaho had them until recently, if I recall.

[vdeane]

I never really understood why NCUTCD thought having a black sign convey information only applicable at night was such a good idea, either.

Probably because white is associated with day and black with night.

[corco]

The far west states never had them. 
iPhone

Utah did prior to 1974. They used the signs with the first digit having a non-reflective daytime number and a retroreflective nighttime number behind it, so your headlights would reflect the nighttime speed.

The ones I saw on US 550 south of Montrose CO specify that the 55mph night limit applies 5pm-7am from September to May (the day limit is 60mph). Not sure what happens the other three months, like July when I was there, though obviously "night" is shorter.

There were more of those nighttime, wildlife zone limits in the mountains. Most were west of the Continental Divide, but one was on U.S. 24 north of Buena Vista. They were only in effect during the fall and winter months. I think CDOT has done away with them, though, because they were not effective.

Utah isn't far west.  I'm talking about Washington, Oregon and California.  Idaho had them until recently, if I recall.

Nope

[1995hoo]

I never really understood why NCUTCD thought having a black sign convey information only applicable at night was such a good idea, either.

Probably because white is associated with day and black with night.

It's clearly racism. White is used for the nice higher daytime speed limit everyone likes and black is used for the lower nighttime speed limit that annoys people. Randy Marsh would be proud.

[J N Winkler]

There were more of those nighttime, wildlife zone limits in the mountains. Most were west of the Continental Divide, but one was on U.S. 24 north of Buena Vista. They were only in effect during the fall and winter months. I think CDOT has done away with them, though, because they were not effective.

Do you happen to know when this determination was made?  I went to Colorado on a roadtrip (US 160 corridor mostly from Walsenburg to Cortez, with a loop that included the Million Dollar Highway length of US 550) over Labor Day weekend in 2012, and found these wildlife speed limit signs in extensive use.  When I did some Web research afterward (not just on these signs, but also the wilfully obscure MEPDG signs), I found a CDOT press release touting them.

I find your 50/55 MPH speed limits on two lane roads fast because the visibility is so limited compared to what I am used to.

I remember driving US 501 between Lynchburg, Virginia and Roxboro, NC:  55 limit through rolling Piedmont hills.  The cross-section was definitely dated, with narrow ROW, no shoulders, ditch slopes starting right at the edge line, and hills with k-values almost certainly lower than modern Green Book minimums.  Lane width was probably eleven feet.  It was a fun trip but 55 definitely felt fast and I was lucky not to encounter a dropped log or confused dog in the middle of my lane, forcing me to test my stopping distance.

Eastern and many Midwestern states tend to have rural arterial systems that sit just below the principal arterials (freeways and rural expressways) and are built to modern geometric design standards, but away from this you are largely at the mercy of the topography, and it tends to be very hit and miss whether states set speed limits that are consistent with safe stopping sight distances.  The differences between neighboring states in speed limit policy (e.g., Kansas versus Nebraska) tend to be especially stark here.

[silverback1065]

There were more of those nighttime, wildlife zone limits in the mountains. Most were west of the Continental Divide, but one was on U.S. 24 north of Buena Vista. They were only in effect during the fall and winter months. I think CDOT has done away with them, though, because they were not effective.

Do you happen to know when this determination was made?  I went to Colorado on a roadtrip (US 160 corridor mostly from Walsenburg to Cortez, with a loop that included the Million Dollar Highway length of US 550) over Labor Day weekend in 2012, and found these wildlife speed limit signs in extensive use.  When I did some Web research afterward (not just on these signs, but also the wilfully obscure MEPDG signs), I found a CDOT press release touting them.

I find your 50/55 MPH speed limits on two lane roads fast because the visibility is so limited compared to what I am used to.

I remember driving US 501 between Lynchburg, Virginia and Roxboro, NC:  55 limit through rolling Piedmont hills.  The cross-section was definitely dated, with narrow ROW, no shoulders, ditch slopes starting right at the edge line, and hills with k-values almost certainly lower than modern Green Book minimums.  Lane width was probably eleven feet.  It was a fun trip but 55 definitely felt fast and I was lucky not to encounter a dropped log or confused dog in the middle of my lane, forcing me to test my stopping distance.

Eastern and many Midwestern states tend to have rural arterial systems that sit just below the principal arterials (freeways and rural expressways) and are built to modern geometric design standards, but away from this you are largely at the mercy of the topography, and it tends to be very hit and miss whether states set speed limits that are consistent with safe stopping sight distances.  The differences between neighboring states in speed limit policy (e.g., Kansas versus Nebraska) tend to be especially stark here.

do wildlife speedlimit signs look any different than night and normal speed signs?

[1995hoo]

Heh. I used to travel 501 between Lynchburg and Durham all the time and I can think of more than one time–all during bright daylight, mind you–when I was doing over 90 mph between Brookneal and Halifax and I thought it felt perfectly reasonable. I hasten to note this would have been between 1995 and 1998 so I was a lot younger and a whole lot dumber! Nowadays I would never consider going anywhere close to even 70 on there.

With that said....I've always felt the imposition of the same 55-mph speed limit on both two-lane roads with blind hills, no shoulders, etc., and Interstate highways with 4+ lanes on each side seriously reduces the credibility of the assertion that speed limits are about "safety." Sure, there are some Interstates that merit a lower speed limit (New York City's are a great example). But in many cases in the East, 55 is imposed solely out of some blind adherence to a principle along the lines of, "urban areas inherently require lower speed limits."

[cjk374]

If you're gonna have a night speed limit, why not have a rain one too? Or an ice one?

Alabama has wet speed limits on US 231 and 431 south of Huntsville, but the goog's images apparently aren't new enough.