Splitting All City into walking routes

Hi,

I am pretty new to this service and need a little help after searching for some days.
I was not able to find what I am looking for. Sorry if it is a repeated question that I missed on my hunting.

I am working on a project probability for a Chinese postman problem but may be there is other way.
To be short … 10k to 100k long/lat city walking points that I need to split in mote or less 400 with some optimizations like fastest, shortest or less street crossing.

Any sugestion ?
At least any way to check if a route with 400 poins is safe / possible to do walking ? Loke avoiding cross roads ?

Reallu appreciate any insights