How come there is no Interstate 1, 2, 3, ....31, 32, 33, 34, etc ?

[roadman65]

As far as I-2 goes, it is a waste right now of a good number as I-97 is in Anne Arundel County, MD.

No. There aren't any other corridors I-2 could reasonably be used for. I-97 has some (DE 1, Wilmington-Myrtle Beach connector, etc.)

If it were going further like to Laredo or even El Paso, yes.  For what it is doing it should be an x69 unless later on they extend it.  Also, Florida along FL 80 could use an I-2 if it were upgraded to freeway.  Highly unlikely, but it would fit in there perfect.

[hotdogPi]

What about MA 2, which is a freeway, but not Interstate standard (because of at-grades) between exits 27 and 33?

A good route number for MA-2 would be I-92. While we're at it NH-101 could be I-94. For those I-standard purists I only advocate redesignation for those highways that meet Interstate standards. MA-2 isn't there yet but could be with a nominal investment. Mostly it needs improved ramps that meet high speed standards. Only that portion from Greenfield to Concord really close to qualifying. As for NH-101 that portion from Manchester to Hampton qualifies now.

If you really want, MA 2 could also be an off-the-grid I-28. I-95 would go on I-93's current route, and MA 128 would nominally become I-128.

Except MA 28 is one of the most important non-freeway state routes in Massachusetts.

[Desert Man]

The Interstate freeway system should designate CA route 99, formerly an US highway, to Interstate 9 or I-9, which is in sync with the north to south routes with odd numbers. CA (ex-US) 99 runs from Sacramento, the state capital meeting with I-80 to 20-some miles south of Bakersfield meeting with I-5 in kern county. To call it I-9 is helpful to attract drivers and businesses' attention to the economically struggling towns of the San Joaquin valley, such as Lodi-Stockton, Modesto, Merced, Madera, Fresno-Clovis (the most populous one), Tulare-Visalia and Bakersfield. There are 3 freeways south of Stockton: the I-205 and I-580 in the town of Tracy, and CA 120 around Lathrop and Manteca, bedroom communities for the SF Bay and Sacramento metro areas. I have no idea why there isn't an I-9 already, but the "99" exists and it needs a transportation facelift.

[wdcrft63]

The Interstate freeway system should designate CA route 99, formerly an US highway, to Interstate 9 or I-9, which is in sync with the north to south routes with odd numbers. CA (ex-US) 99 runs from Sacramento, the state capital meeting with I-80 to 20-some miles south of Bakersfield meeting with I-5 in kern county. To call it I-9 is helpful to attract drivers and businesses' attention to the economically struggling towns of the San Joaquin valley, such as Lodi-Stockton, Modesto, Merced, Madera, Fresno-Clovis (the most populous one), Tulare-Visalia and Bakersfield. There are 3 freeways south of Stockton: the I-205 and I-580 in the town of Tracy, and CA 120 around Lathrop and Manteca, bedroom communities for the SF Bay and Sacramento metro areas. I have no idea why there isn't an I-9 already, but the "99" exists and it needs a transportation facelift.

If Wikipedia can be believed, its page for Interstate 9 says "Interstate 9 has been proposed by Caltrans for State Route 99 in central California. It would go from the split with I-5 at Wheeler Ridge (Wheeler Ridge Interchange) north through Fresno to Stockton, where the proposed route turns west via the State Route 4 freeway to a terminus at I-5 in the central part of that city."

[kkt]

The Interstate freeway system should designate CA route 99, formerly an US highway, to Interstate 9 or I-9, which is in sync with the north to south routes with odd numbers. CA (ex-US) 99 runs from Sacramento, the state capital meeting with I-80 to 20-some miles south of Bakersfield meeting with I-5 in kern county. To call it I-9 is helpful to attract drivers and businesses' attention to the economically struggling towns of the San Joaquin valley, such as Lodi-Stockton, Modesto, Merced, Madera, Fresno-Clovis (the most populous one), Tulare-Visalia and Bakersfield. There are 3 freeways south of Stockton: the I-205 and I-580 in the town of Tracy, and CA 120 around Lathrop and Manteca, bedroom communities for the SF Bay and Sacramento metro areas. I have no idea why there isn't an I-9 already, but the "99" exists and it needs a transportation facelift.

If Wikipedia can be believed, its page for Interstate 9 says "Interstate 9 has been proposed by Caltrans for State Route 99 in central California. It would go from the split with I-5 at Wheeler Ridge (Wheeler Ridge Interchange) north through Fresno to Stockton, where the proposed route turns west via the State Route 4 freeway to a terminus at I-5 in the central part of that city."

Follow the citation from Wiki.  It's a long-term vision, not a proposal.

[Zzonkmiles]

So, where would an I-1 be placed? I think US 101 is much too famous to be renumbered.

[tidecat]

So, where would an I-1 be placed? I think US 101 is much too famous to be renumbered.

Ideally you would renumber CA 1, but large portions of CA 1 are not even four lanes, and numerous sections are concurrent with US 101.

[national highway 1]

So, where would an I-1 be placed? I think US 101 is much too famous to be renumbered.

Ideally you would renumber CA 1, but large portions of CA 1 are not even four lanes, and numerous sections are concurrent with US 101.

Think FritzOwl. He has 'advocated' for all of CA 1 turning into his I-1. 
But California doesn't allow duplication between Interstate, US or State Route numbers, unless it's an continuation of the route with the same number , eg. CA 110-I-110, CA 15-I-15, CA 210-I-210.

[SSOWorld]

So, where would an I-1 be placed? I think US 101 is much too famous to be renumbered.

Ideally you would renumber CA 1, but large portions of CA 1 are not even four lanes, and numerous sections are concurrent with US 101.

Think FritzOwl. He has 'advocated' for all of CA 1 turning into his I-1. 
But California doesn't allow duplication between Interstate, US or State Route numbers, unless it's an continuation of the route with the same number , eg. CA 110-I-110, CA 15-I-15, CA 210-I-210.

of which CA 210 should be I-210 already.

[Brandon]

So, where would an I-1 be placed? I think US 101 is much too famous to be renumbered.

As far as I'm concerned, I think we should just drop the "H" on I-H1, I-H2, etc, and just call them I-1, I-2, I-3, and I-201.  Hence, 1, 2, and 3 all fit where they are and would just be duplicate routes (in the case of I-2) as I-76, I-86, etc.

[Rothman]

So, where would an I-1 be placed? I think US 101 is much too famous to be renumbered.

As far as I'm concerned, I think we should just drop the "H" on I-H1, I-H2, etc, and just call them I-1, I-2, I-3, and I-201.  Hence, 1, 2, and 3 all fit where they are and would just be duplicate routes (in the case of I-2) as I-76, I-86, etc.

Having driven on all the I-Hs except I-H2, I consider this blasphemous.

[kkt]

So, where would an I-1 be placed? I think US 101 is much too famous to be renumbered.

Ideally you would renumber CA 1, but large portions of CA 1 are not even four lanes, and numerous sections are concurrent with US 101.

Ideally you would leave CA 1 the heck alone.  It's a practically perfect scenic drive.  There is no room to make it 4 lanes, the geometrics would not support freeway speeds, and it requires frequent left turns for beach access.  People who are in a hurry take US 101 or I-5, and they should continue to do so.