In the case of hard core restrictions such as horizontal price fixing which occur when the conference tariff is set and charges and surcharges are jointly fixed, the negative effects are , from transport users' point of view, very serious since they consider that conferences operate for the benefit of the least efficient members and call for their abolishment.
Ievērojamu ierobežojumu (piemēram, horizontālā cenu noteikšana) gadījumā, kuri rodas, ieviešot konferences tarifu un kopīgi nosakot papildu maksas, negatīvās sekas no lietotāju viedokļa ir ļoti nopietnas, jo tie uzskata, ka konferences darbojas to dalībnieku labā, kuru efektivitāte ir vismazākā, un aicina atcelt konferences.