Cities where development does not follow the freeway

[US81]

I was noticing that in Dallas, the development does not follow I-45 like it does for I-30.  In fact the typical interstate interchange does not begin until several miles south of I-20.

I do not know about I-20 as that is one DFW Metroplex freeway I have yet to clinch.

Those two are strange to me, too.  Even north of I-20, I-45 is like a drive in the country, not far from downtown.  I don't know if it has to do with the flood plains or what, but that area seems to repel development.

I-20 is (or seems to me) more rural on the Dallas side than the Fort Worth side.  The speed limit is higher to the east, 65 in Dallas County and 60 in Tarrant.  Before environmental speed limits it was 70 in Dallas and 65 in Tarrant.  There's even a piece of it west of Spur 408 that, other than massive 8-lane freeway, almost seems like a rural Hill Country highway.

Also, I-35E seems to get more urban for a while going south from I-20, away from Dallas.  This may have to do with zoning and other municipal regulations in DeSoto and Lancaster compared with Dallas, which ends right about at I-20.

I used to drive semi-regularly between Dallas/Ft Worth, Houston and San Antonio (this was mostly in the late 1990s, early 2000s). I was always struck with how different development was between I-45 and I-35. Most towns and cities along I-35 spread over to the interstate, even when it was several miles away from the old US highway the interstate replaced. I never had to plan gas or food stops along I-35 because there was an option of some sort every few miles. By contrast, there would seldom be any visual evidence on I-45 itself of towns that were only one or two miles away. Between Corsicana and Huntsville one used to have to leave the interstate to get gas and food; one just had to know that Centerville or Madisonville were large and close - no truck stops, no fast food, and poor signage, at least back then. I-10 was midway between these: rural stretches, but having gas stations and fast food from the larger towns like Columbus extending to and visible from the freeway.

I remember being puzzled by these differences but never understood why they existed.