Put the query and file between double quotes and it should work.
bcp "select * from TRAFICO1.dbo.HECHOS_TRAFICO_DATOS_PREPAGO_201308_5338_5347" queryout "\\trafico\Historicos_Tablas\PLANOS_TRAFICO\HECHOS_TRAFICO_DATOSPREPAGO_201308_5338_5347.txt" -c -t"|" -Strafico\traficosql -T