Speed limits on freeways without corresponding signage

[Techknow]

What freeways/interstates that you drive on that lack signage of the speed limit, making the speed limit ambiguous or default to the maximum of the state?

To be clear I'm not talking about freeways/interstates with no speed limits, but rather the lack of signage of the speed limit or an implied speed limit.

I driven on the north end of I-280 in San Francisco in both directions several times, and each time I go past the US-101/Alemany Interchange I have never seen a Speed Limit 65 sign from that point to where the freeway ends. The first time I seen a Speed Limit sign is after the interchange while going southbound. Meanwhile the speed limit on US-101 drops from 55 MPH to 50, and I-80's speed limit is 50 MPH until halfway through the Bay Bridge, so I think this lack of signage is pretty specific to I-280. Perhaps this is because the freeway starts/ends in 2 miles?

I tried looking for a Speed Limit sign on GSV but I only found a Truck Speed limit sign which is 55 MPH and that's pretty standard. I never seen a 60 MPH speed limit in the SF Bay Area, I would assume the speed limit is 65.

Another example of this is that I have never noticed a speed limit sign on CA's I-380 in either direction so I just assume the speed limit there is always 65 MPH

[pianocello]

In grad school, the project I worked on involved finding the speed limits for all Interstates in the country. Since states were sporadic in having that information in a way that a researcher could easily find, Google Street View was a godsend.

That said, most states are pretty good about posting a speed limit sign pretty close to every on-ramp. Especially in rural areas where interchange density is relatively low.

The one exception to that that I remember is California. One particular stretch I remember was I-5 between downtown LA and I-210, that seemed particularly devoid of speed limit signs. I don't know how y'all are supposed to know what the speed limit is if the first sign is several miles after the on-ramp.

[jeffandnicole]

I've brought up in the past, when the NJ Turnpike still used the older-generation variable speed limit signs, so many were broken you could drive upwards of 30 miles at one point without encountering a working sign.  In NJ, the default limit is 25, 35 and 50 mph, so by default the limit could be 50 mph.  The Turnpike's Regulations though have it documented that it is 65 mph.  Oddly, when originally crafted, they started the 65 mph at Milepost 1.0, not 0.0.  The regulations were silent as to the limit between 0.0 and 1.0.  The first speed limit sign wasn't posted until about MP 1.5.  Everything's been updated, and none of these issues currently exist.

The DRPA and DRBA Bridge agencies between PA/DE and NJ have an odd tendency to post their speed limit at the end of their jurisdiction, and NJDOT doesn't quickly post their limit at the beginning of their jurisdiction, leading to a little vagueness. In all cases, the actual limit is higher than the statutory limit for unsigned roadways.

[Techknow]

In grad school, the project I worked on involved finding the speed limits for all Interstates in the country. Since states were sporadic in having that information in a way that a researcher could easily find, Google Street View was a godsend.

That said, most states are pretty good about posting a speed limit sign pretty close to every on-ramp. Especially in rural areas where interchange density is relatively low.

The one exception to that that I remember is California. One particular stretch I remember was I-5 between downtown LA and I-210, that seemed particularly devoid of speed limit signs. I don't know how y'all are supposed to know what the speed limit is if the first sign is several miles after the on-ramp.

Oh, interesting observation about California. This void of speed limit sign only happens for at most a few on-ramps in my experience, but the I-210 intersection is pretty far from downtown LA which makes for a huge gap for those who want/need to know the speed limit (never mind the traffic levels there!)

I just checked the state's driver's manual and it mentions only a 55 MPH limit for two-lane roads/highways if there's no signage. The max freeway speeds (65 MPH for urban areas, 70 MPH for some rural areas) are found in Caltrans' site but most people I imagine wouldn't visit their site. So yeah I don't know how drivers would generally know if there's no signage.

When you said most states, what are the states that are the exception, if any?

I've brought up in the past, when the NJ Turnpike still used the older-generation variable speed limit signs, so many were broken you could drive upwards of 30 miles at one point without encountering a working sign.  In NJ, the default limit is 25, 35 and 50 mph, so by default the limit could be 50 mph.  The Turnpike's Regulations though have it documented that it is 65 mph.  Oddly, when originally crafted, they started the 65 mph at Milepost 1.0, not 0.0.  The regulations were silent as to the limit between 0.0 and 1.0.  The first speed limit sign wasn't posted until about MP 1.5.  Everything's been updated, and none of these issues currently exist.

The DRPA and DRBA Bridge agencies between PA/DE and NJ have an odd tendency to post their speed limit at the end of their jurisdiction, and NJDOT doesn't quickly post their limit at the beginning of their jurisdiction, leading to a little vagueness. In all cases, the actual limit is higher than the statutory limit for unsigned roadways.

Interesting, I never seen variable speed limit signs used in California, but I don't know how I'd feel if I paid to use a toll road and see such signs not working. Otherwise I guess in those places speeding isn't such an big issue there

[pianocello]

Oh, interesting observation about California. This void of speed limit sign only happens for at most a few on-ramps in my experience, but the I-210 intersection is pretty far from downtown LA which makes for a huge gap for those who want/need to know the speed limit (never mind the traffic levels there!)

I just checked the state's driver's manual and it mentions only a 55 MPH limit for two-lane roads/highways if there's no signage. The max freeway speeds (65 MPH for urban areas, 70 MPH for some rural areas) are found in Caltrans' site but most people I imagine wouldn't visit their site. So yeah I don't know how drivers would generally know if there's no signage.

When you said most states, what are the states that are the exception, if any?

To be fair, there were a few speed limit signs in that stretch but not nearly as many as I would have expected given the ramp density. And not as many as similar roads in other metro areas that I'm more familiar with. IIRC, it took me forever to find the first Speed Limit 65 sign northbound (which was itself further south than I thought it would be, having never been there).

As for other states, it was a few years ago so I don't remember fully which states are better or worse than others so it's hard for me to give a straight answer to your question. All I remember is that a lot of states were pretty rigid with the speed-limit-sign-after-every-on-ramp rule of thumb, and others were a bit more spotty. None stood out to me as much as California, though.