'Vrije reizigers' refers to passengers travelling on public transport services who are not making use of a concessionary arrangement for specific groups of public transport users (e.g. pensioners, disabled, schoolchildren, etc.).

-> "Naast eerdergenoemde doelgroepen kunnen ook “vrije reizigers” gebruik maken van de deeltaxi. Onder de vrije reizigers valt iedereen die niet voor een WVG- of seniorenpas in aanmerking komt."
[WVG = Wet Voorzieningen Gehandicapten]
http://www.zundert.nl/did/pagina.html?pag=19&item=100838

-> "2.7 More extensive survey work was carried out during the evening peak where kerbside occupancy surveys of buses leaving city centres were augmented by on-bus counts of passengers stratified by concessionary and ***non-concessionary passengers***."
http://www.scotland.gov.uk/library5/transport/mflbt-03.asp

-> "Survey data provide the lengths of journeys travelled by each type of concessionary passenger. These are used in conjunction with the operator's fare tables to calculate the cash fares that would have been paid by ***non-concessionary passengers*** making the same journeys."
http://www.centro.org.uk/wwwroot/CorpInfo/Concessionary_Trav...