Global Script Links Page
It is generally agreed that a Roman script - English script without diacritics - would be adequate for an initial IAL of 5 vowels and 17 - 22 consonants. Only a few redundant or duplicated letters - [c, g, j, q, x] - would need to be specified or reassigned for phonemic reasons - and the apostrophe might be used to denote the glottal stop, as in English. This script is easily the commonest, world-wide, and every educated person is familiar with it.
But what would happen next? As soon as the phonology expanded beyond this initial level an English script would cease to be phonemic.
The IPA is often mentioned at this point, but it was never designed to be a script as such, and certainly doesn't lend itself to handwriting. A better system would seem to be Brasseur Universal Code:
According to Burke Brown (mentioned in the first link below) this script was developed by Larry Brasseur in the late 1970s, and the correspondence with the I Ching and Braille was discovered afterwards.
Binary-coding allows Brasseur Script to represent the largest phonology without difficulty. It's certainly ingenious, logical and economical - but does it work aesthetically for human beings as well as machines? Perhaps a few curves wouldn't go amiss....
Another script with the potential to embrace a vast phonology - the whole of the IPA - is Nurigeul. And unlike Brasseur Code it seems to appeal to both sides of the brain:
Is there a better script out there?