Why does I-35 have an E or W in its route number in Texas and Minnesota?

[bing101]

http://en.wikipedia.org/wiki/Interstate_35E_%28Texas%29
http://en.wikipedia.org/wiki/Interstate_35W_%28Texas%29

http://en.wikipedia.org/wiki/Interstate_35E_%28Minnesota%29

http://en.wikipedia.org/wiki/Interstate_35W_%28Minnesota%29

According to Wikipedia I-35w in Minnesota is really hidden MN-394

In Texas I-35e is a section of US-67 and US-77.

I know in the past in California in the 1960's there was an I-5w now known as I-580 and it took the section US-50 Bay Area Portion before US-50's end went to Hidden I-305 and Business 80. Was one of the I-35's supposed to follow the Sacramento Model such as Business 80 and I-80 model.

[english si]

I know in the past in California in the 1960's there was an I-5w now known as I-580

and I-80 and I-505.

There was also a third I-35W, heading north from Wichita to I-70 (now I-135). There were several more, as seen on this wikipedia list

Recently I-69 has picked up E/C/W splitting at it's southern end - only I-69E (US77) and I-69C (US281) currently have signs, but I-69E (US59) will also be suffixed, from what we can make out.

Was one of the I-35's supposed to follow the Sacramento Model such as Business 80 and I-80 model.

No, only a couple of places in the Carolinas (Greensboro, Winston Salem, Spartenburg) and Sacramento did that when moving the main route onto a new freeway.

The longer/more important suffixed route became 2dis. The shorter ones became 3dis. MSP and DFW couldn't work out what downtown of their twin cities should be denied the main 2di and kept the split.

[TheStranger]

The longer/more important suffixed route became 2dis. The shorter ones became 3dis. MSP and DFW couldn't work out what downtown of their twin cities should be denied the main 2di and kept the split.

The Riverside I-15E/I-215 switch (after I-15 was moved west to what had been a portion of Route 71 and all of Route 31)  seems to have been more of a mechanism to get Interstate funding for new-terrain freeway between Corona and Devore.

[NE2]

According to Wikipedia I-35w in Minnesota is really hidden MN-394

That's a legislative number. Every Minnesota highway has one.

[bing101]

I know in the past in California in the 1960's there was an I-5w now known as I-580

and I-80 and I-505.

There was also a third I-35W, heading north from Wichita to I-70 (now I-135). There were several more, as seen on this wikipedia list

Recently I-69 has picked up E/C/W splitting at it's southern end - only I-69E (US77) and I-69C (US281) currently have signs, but I-69E (US59) will also be suffixed, from what we can make out.

Was one of the I-35's supposed to follow the Sacramento Model such as Business 80 and I-80 model.

No, only a couple of places in the Carolinas (Greensboro, Winston Salem, Spartenburg) and Sacramento did that when moving the main route onto a new freeway.

The longer/more important suffixed route became 2dis. The shorter ones became 3dis. MSP and DFW couldn't work out what downtown of their twin cities should be denied the main 2di and kept the split.

I know the Eastern half Business 80 is hidden CA-51. But look at Texas they have I-69c, I-69W and I-69E. But I-69 Parent Route is still being planned as of 2013.

http://en.wikipedia.org/wiki/List_of_suffixed_Interstate_Highways

[PHLBOS]

FWIW, here's an excerpt from one of the Wiki web-links from the OP's post as towards why I-35E/W in DFW & MSP were allowed to maintain their suffixed identities:

In the case of I-35, since both branches return to a unified interstate beyond the twin cities of Dallas and Fort Worth (as well as Minneapolis & St. Paul), the AASHTO committees allowed the suffixes to remain.

All Most of the previously suffixed Interstates (since renumbered) were more like branch-offs rather than parallel splits.

[TheStranger]

All of the previously suffixed Interstates (since renumbered) were more like branch-offs rather than parallel splits.

I-59B (never signed in field), I-5W, and I-15E were parallel splits.

[PHLBOS]

I-59B (never signed in field)

In all honesty, should we really count that one?

I-5W, and I-15E were parallel splits.

My bad, I've since corrected my previous post accordingly.