What is the rule for 50% off on Guizhou Expressway?

According to inquiries, car owners can only find out the 50% discount on Guizhou Expressway on the official website as follows:

According to Guizhou’s tourism preferential policy between June 16 and August 31, 2023, other provinces When a Type 1 passenger bus exits a station on a highway in Guizhou Province, using the ETC electronic payment method will receive a 50% discount, that is, half price. This offer is only valid from 0:00 on Friday to 24:00 on Sunday. Such regulations provide tourists with a flexible time window during which they can travel around Guizhou at a lower cost.