First off, make sure you are using the latest TileZed and WorldEd, found here:
https://theindiestone.com/forums/index.php?/topic/44033-latest-tilezed-and-worlded-december-21-2021/

Now, In BuildingEd there is a new "Legend" feature that shows up on the right hand side underneath your list of buildings.
For each of your buildings, select it in the list and then click on the Legend drop down and select the most appropriate option, this will make the building be coloured correctly when being displayed on the new in game mapping system.

If you're making changes to buildings already placed on your map then don't forget to "generate lots" again in WorldEd!

Next up, to get roads to be displayed on your map using the new in game mapping system you need to open your cell in WorldEd and draw a poly over your road with the new tools (the rectangle tool is the main one to use unless you have curved roads), then on the left of the window, in the "ingamemap" tab click on your new poly then click on the add button just below to open a key/value window, in key type "highway" and in value use either "primary", "secondary" or "tertiary" or "trail". You can then use the copy and paste buttons to the right of the "add" button to speed things up.

Once all roads have been added then go to world view and select all cells, then in the "ingamemap" option at the top of the screen select "generate building features", once done do the same for "genereate water features" and "generate tree features".
The above pic shows a cell which has had it building, tree and water features generated as well as having the highways added using the new "ingamemap" poly tools.

Once all of these are done you can select the "Write features XML" option, select the same folder you export your map files to as these new xml and xml.bin files that are created will need to be put in the same folder as all of your bin and lotheader files.

As long as you inlcude your worldmap.xml and worldmap.xml.bin alongside your maps lotheader and bin files then your maps buildings and roads should be displayed using the new in game map system.

Here are a couple of in game examples of Bedford Falls using the above method and the new in game map system: