Step one

Last night I printed up some graph paper and got started on the kid's playmat. WOW, I gave myself a migraine. It's big, 42x42 and I had to use two sheets just to lay it out.
I asked my oldest son to share some of his ideas because he loves the math and symmetry to crochet. He has asked me to teachhim, but it's too sedentary a hobby for a growing boy and he quickly loses interest. Pattern conception, however, is right up his alley. He drew me a 'plan' last night as a visual aid. there is a big train track with an engine, a really squiggly road, and a big lake all populated by random people, cars, and trees. the road might not work without some tweaking, but he is really fun to collaborate with and i look forward to the challenge.

My 'plan' is now done. There is a straight railroad track across the top, brown rail road ties intersected by silver/gray track and the background is a tan-brown with random edging to simulate dirt. To the left side of the mat and crossing over the tracks is a road, black with yellow lines down the center, white 'stop here' lines on either side of the tracks, and it also has a tan 'dirt' edging. The road is straight til just after it crosses the tracks, then there's a T intersection and that crossroad is all curvy. not squiggly, but definitely not straight.

The straight lines were easy peasy, the random edges, meh, it was more about the organic flow than precise lines, but the curvy road - that was HARD. It was only natural to me to keep the edges of the road the same number of squares apart on the graph, but that resulted in pinched looking tarmac and an awkward collision of numbers and feel. Ugh. Right about then I discovered that an eraser on a #2 pencil can make graph lines disappear.
I went with the look and feel as a priority because after all, this is for little kids. The lake was super easy as well since it SHOULD be wavy and I placed it in the lower right corner to counterpoint the track and road intersection in the top left corner.
Are you with me so far? Hopefully you can visualize it all fairly well. Last night my 6 year old was haltingly trying to explain what he was thinking and it made little sense, so he paused, tilted his head to the side and asked me, Mom, do you know what visualization is?
This led to him needing to literally draw me a picture because it seems I really have no idea how to visualize with him.
Back to the concept at hand. the road, track, and lake seem fairly simple to place on a big square and the spaces left are going to be green. Like the tan 'dirt' edges, the green will have a paler green edging where the grass is close to the dirt. There is a dirt rim around the lake as well and then the lake water will be pale blue for shallows and dark blue for depths.
Breathe in, breathe out, visualize with me. Are you there? OK, moving on to much simpler ideas.

There will be vehicles on land and water - a little flatbed pickup truck, a sedan, a train engine, a sailboat. There will be a home with a nice front porch, a general store, a stop sign, and a RRx sign. Pine trees, small bushes and flowerbeds for landscaping.
All of these are going to be stuffed and flat bottomed to stay upright on the mat, and I am considering a couple of fish stitched onto a coin-shaped blue background for the lake. i don't know about people or animals yet, there are a lot of details and pieces as it is and I fought off a migraine just dealing with THIS much last night.
I sort of tossed ideas around for a vest, but it was too much for me after the small town I just created. My Mick wants a mountain now. thankfully that is really easy. This is going to be a huge project!