Hello and welcome. This thread chronicles my modding adventures concerning various new streets.
Thusfar I have basically done a whole bunch of experiments, detailed below, but my aim is to create a coherent, so-called historic street mod.
Allright, enough with the chit-chat let's get on with it.

Yay, the first override ever. Texture taken from the cp texture pack.

Some hours in photoshop later and one gets this.

And while at it, why not do the other CP texture as well? Also notice the wide curves, the colour difference is a pain to get rid off.
I also did the smallest 'road' textures found in the CP pack, which somehow I don't have a picture of anymore. Now I had three texture sets but this was only the beginning really. At the time I also learned about T21's and incidentally had stumbled across a remarke made by Barby, about the seemingly little know fact growables can be network enabled too. In my mind, this opened up a whole new world of possibilties, the majority of which turned out to be deadends later on. In haste I threw some things together.

Hm, not too pretty but that's what happens when one rushes into action. You do however see the three different CP textures, colour corrected so they would match each other. But the transition between the different street tops, caused by the difference in zoning, is one thing that can't be eliminated. Needless to say it is an eyesore. And so are the empty stretches of sidewalk, even if it would be tiled properly. This whole exercise did however made me realize seamless transitions between streets and lots were possible. For this to happen I again turned to the CP texture pack.

I added 'sidewalks' to the overlays and took a matching green basetexture as sidewalk. I applied the same textures to network enabled lots and finally ended up with something which for me was pleasing to the eye. But it didn't stop me messing around.

Which gave me the idea to turn the whole thing upside down. By which I mean, to ditch the small dirt road and instead make the sidewalk appear as street top surface. The actual street textures now function as sidewalks and a much greater variety in sidewalks can be achieved, since they are wealth dependent.

Like this, agriculture is yellow, residential is green and unzoned is well, unzoned with some speckles on the side. Now it is possible to have seamless transitions and still some variety in appearance.
I was making good progress on this when one night, while lurking in the MD archives I had a brainwave. Wouldn't it be awesome if everything could be covered with mayor-mode ploppables and still be functional? If streets would blend perfectley into their surrounding and together with network enabled lots, everything would fit together and look as wild and as natural as simcity can get? With network enabled lots and T21's, it would be doable. But upon realisation of the tedious work involved, I dismissed the idea as quickly as it came. Only to find myself pondering on it the next few days until finally I thought, why not? At least give it a try. And so I did just that.

Although I still like the idea and the way it came out, with the benefit of hindsight it was pretty crazy, if not sheer madness to do so. Let me explain why.
For starters, the streets added a ton of props, making it a heavy on resources which resulted in a horrible lag. I did think about this beforehand but still, the game became extremely unresponsive and all the sudden prone to crashes, both things I normally don't experience. To check if it wasn't anything else causing this, I removed the T21's and reversed the streets back to plain textures. It made a noticable difference.
Secondly, it only looks good in zoom 2 (or 5, depending how you count). And finally because of the way T21's work, repetition is inevitable unless one makes multiple T21's for every single network tile and every single Network_Place_ID. This would amount to a minimum of 32 T21's just going straight ahead.
Ah well, it was a fun week and it did leave me with all the T21's required for a proper street mod so I began to wonder, what would one see out on the streets during, say the late 17th / early 18th century? Carriages for sure, people walking around, some animals too perhaps. The streets would be flanked by fences, or maybe some low rock walls or just random weeds. I began gathering props and meanwhile polishing the textures a bit. This leaves me at the current state of affairs.

Rural: Dirt top sidewalk, yellow overlays, various T21's

After a suggestion from a friend I'm now adding carriage tracks to the overlays.

Did I mention, it's an override for SAM 3, PEG Dirt roads. Wide curves look a bit odd.

Residential: Dirt top sidewalk, green overlays, various T21's.

Something made last week, white top sidewalk with two kinds of purple overlay for SAM 7.
So that's it. Basically I've got like 10 different texture sets and all the t21's I could ever wish for at my disposal and still somewhat clueless what to do with it all.

Well not really but I do appreciate constructive critism and suggestions, so if you have something on your mind, please leave me a comment. Bye for now.