are they simple large letters?
you said "white background" but you didn't say reflective white... so you may not want to print red on reflective white for 2 reasons. At 16" x 24" you will, of course, have a splice AND you will be using a lot of expensive white reflective vinyl that you may not need. You mentioned Edge printing, so I'll assume there is a reason for that... but if the reason is just to save labor on weeding... how much weeding is there really? If you don't need the background to be reflective, you might save quite a bit of money on the amount of expensive vinyl required for this job, if you are willing and able to weed cut red reflective vinyl instead. You can buy pre-painted white blanks too (depending on what substrate you're using) and maybe save time on application.