Which Phoenix area freeways do you think could support 70 mph speed limits? (Queen Creek: fit in, construction)

[Pink Jazz]

With some states now introducing 70 mph speed limits in urban areas, I easily think some of our Valley freeways (which are among the nation's best designed) can easily support 70 mph speed limits as well.

I was wondering, which Phoenix area freeways do you think can support 70 mph speed limits?


Here are my picks:

• I-10 from SR 85 to 43rd Avenue
• I-10 from Baseline Road to Queen Creek Road
• I-17 from Loop 101 to Carefree Highway
• Loop 101 Agua Fria Freeway
• Loop 101 Pima Freeway from I-17 to Pima Road
• Loop 101 from Shea Boulevard to Loop 202 Red Mountain Freeway (after construction is complete, obviously)
• Loop 202 (all)
• US 60 Superstition Freeway (all)
• Loop 303 (after full freeway conversion)

Also, I would raise the portions of I-17 and SR 51 that are currently 55 mph to 60 mph. As for raising the Loop 101 Price Freeway to 70 I am not so sure due to the higher amount of traffic.

What does anyone here think?

[JGMotorsport64]

I've read studies that higher speed limit freeways can be safer than low speed limit freeways.

To answer your question, I've found the average travel speed up to 80mph sometimes around town, I think they all CAN support it, but in the age of texting who knows how many more deadly rollovers this might cause.

[Pink Jazz]

Originally Posted by JGMotorsport64

I've read studies that higher speed limit freeways can be safer than low speed limit freeways.

To answer your question, I've found the average travel speed up to 80mph sometimes around town, I think they all CAN support it, but in the age of texting who knows how many more deadly rollovers this might cause.

Note that I excluded the inner city portion of I-10, I-17 south of Loop 101, and SR 51. I-10 within central Phoenix for many years remained at 55 mph until 2009.

[asufan]

I think most of the highways around town could support 85

[Bates419]

It's already the normal rate of speed so I would say almost all could support the increase. If you driving under 70 on most of these roads you are getting passed quickly and often, increasing your risk.

[Pink Jazz]

Originally Posted by asufan

I think most of the highways around town could support 85

Here in Arizona that is unlikely to happen even in rural areas due to the state's 85+ criminal speeding law, which the state's lawmakers refuse to change. There needs to be at least a 10 mph buffer between the posted speed limit and the criminal speeding threshold.

Note that the southern portions of I-17 and SR 51, as well as SR 143 are posted at 55 mph, and going straight to 70 mph would be a huge increase. I do believe the reason for the lower speed limits on these freeways is due to substandard design (I-17 I think was grandfathered into the Interstate Highway System and would not qualify for an Interstate designation if it were built the same way today).

[Valley Native]

Originally Posted by Pink Jazz

With some states now introducing 70 mph speed limits in urban areas, I easily think some of our Valley freeways (which are among the nation's best designed) can easily support 70 mph speed limits as well. I was wondering, which Phoenix area freeways do you think can support 70 mph speed limits?

All of them could (even I17), and for many reasons. Most modern vehicles are equipped for faster speeds now ... even the cars with V4 engines can accelerate to a higher speed in less time than 20+ years ago. I've heard the tired out argument that Phoenix is an urban area, and should have lower speed limits ... however, the fact that our weather is clear much of the time and our freeways are in generally good condition contributes to fewer traffic issues compared to cities back east. It's actually safer to drive fast on the freeways (so long as conditions allow for it) than slow. The 55 MPH speed limits are obsolete, and should have gone the way of gasohol, pet rocks, disco, streaking, and other bad fads of the 1970s!

[Pink Jazz]

Originally Posted by Valley Native

All of them could (even I17), and for many reasons. Most modern vehicles are equipped for faster speeds now ... even the cars with V4 engines can accelerate to a higher speed in less time than 20+ years ago. I've heard the tired out argument that Phoenix is an urban area, and should have lower speed limits ... however, the fact that our weather is clear much of the time and our freeways are in generally good condition contributes to fewer traffic issues compared to cities back east. It's actually safer to drive fast on the freeways (so long as conditions allow for it) than slow. The 55 MPH speed limits are obsolete, and should have gone the way of gasohol, pet rocks, disco, streaking, and other bad fads of the 1970s!

I do know for the southern portions of I-17 and SR 51, the shoulder widths are substandard, and SR 143 is probably too short for a 70 mph limit. It doesn't matter what vehicles are rated for; speed limits have to be supported by an engineering and safety study (no matter if it is an increase or a decrease), not determined politically or by decree to suit someone's preference. Going with blanket speed limit increases without any study is seriously flawed as proven by South Dakota's recent botched 80 mph blanket increase, requiring I-90 west of Rapid City to be quickly lowered back to 75 mph due to safety concerns.

[ScottsdaleMark]

Originally Posted by Pink Jazz

Here in Arizona that is unlikely to happen even in rural areas due to the state's 85+ criminal speeding law, which the state's lawmakers refuse to change. There needs to be at least a 10 mph buffer between the posted speed limit and the criminal speeding threshold.

Note that the southern portions of I-17 and SR 51, as well as SR 143 are posted at 55 mph, and going straight to 70 mph would be a huge increase. I do believe the reason for the lower speed limits on these freeways is due to substandard design (I-17 I think was grandfathered into the Interstate Highway System and would not qualify for an Interstate designation if it were built the same way today).

As you wisely referenced, criminal speeding is:
When a driver exceeds 85 mph anywhere in the state
When a driver exceeds 35 mph while near a school crossing
When a driver exceeds a posted speed limit by 20 mph in a business or residential area
When a driver exceeds 45 mph when no speed is posted in a business or residential area

This doesn't give much of a buffer for those driving I-10 west toward California, since the speed limit is all the way up at 75 mph. If the speed limits on Valley freeways were raised above 65, surely the incidence of criminal speeding would increase too.

I personally could consider support raising some 55 mph areas to 65 mph, but I don't see much benefit in going from 65 to 70, and I think 75 is too fast for a freeway with so many on and off ramps and stop-and-go driving. I see too many multi-car / rear-end collisions as it is.

[Pink Jazz]

It seems that those advocating for a blanket increase of all Phoenix area freeways to 70 mph or higher just want it to suit their tastes, not factoring any engineering or safety standards. I have very good reasons for my picks since they are among the better engineered freeways in the Valley.