Does anyone know if the old tarjetas are still valid for the tolls on Corridor Sur and Norte? The info I could find seemed to say that as of May 1, only the Panapass would work. If that were true, then there would have been massive traffic jams of cars without the panapass. Sounds like there are only 2 places that "install" the panapass in the car. What is the panapass anyway? Is it a transponder like we have in Canada for the ETRs (Electronic Toll Roads) ?