Australia, so far as I know, is the only country to have implemented an ICAO thought to address the deficiencies in the geometry based runway width limits which most countries use.
As part of the internal requirements in Australia, if an operator seeks to run the aircraft on narrower than "standard" runways the aircraft has to demonstrate its ability under critical conditions to be able to do so with a high degree of probability of not coming adrift .....
B737 was done for TN/AN some years ago for 100 ft/30 m runways (and would be the basis for the appendix to which Mearse refers) .. Citation for 18 m (which was sold to Cessna and formed the basis for the current Citation narrow runway appendix) .. the Diesel 9 was started, but not finished, for 100 ft/30 m (operator really couldn't see the commercial value in putting itself out to provide the aircraft to suit weather etc .. )
... some interesting pix ... those who were involved learnt all about the problems of putting LOOOONG lenses on videos ...
There were a few other aircraft done .. but I can't bring the individual types to mind .....
The main concerns were associated with the crosswind versus Vmcg problem which Mutt and I regularly air in these forums in a vain effort to get people interested in thinking about odd corners of the envelope in which they might periodically find themselves .... and in which they might get bitten badly on occasion .. whilst thinking that all is well ...
Those of us who were involved in some of these test programs came away quite converted believers ..... if you believe that runway width is NOT important for low speed schedule takeoffs .. then you are a sitting duck for a BIG surprise one of these days ...