NRH has these signs. I've marked what I think I understand.

There's also this from Bike Texas,

North Richland Hills - The on-street bike routes are numbered in the same manner as the Interstate Highway System; odd numbers are assigned to north-south routes and even numbers are used for east-west routes. Numbering begins in the southwest corner of North Richland Hills and increases in increments of 10 as the system extends north and east.

And this from the NRH website,

http://www.nrhtx.com/documentcenter/view/588

Does anyone have any more info on these signs? Are there other cities in the DFW that use these?

Thanks