Long-term viability and degressiveness: the route receiving the aid must ultimately prove profitable, i.e. it must at least cover its costs, without public funding.
Elujõulisus pika aja jooksul ja abi järkjärguline kahanemine: liin, millele abi antakse, peab osutuma kindla aja jooksul elujõuliseks, s.t katma vähemalt oma kulud ilma riigipoolse rahastamiseta.