LA PAZ, Bolivia — Bolivian President Luis Arce on Wednesday called for the end of costly highway blockades that have paralyzed parts of the South American country and fueled an increasingly volatile conflict with his main political rival. The economic costs of the blockades over 17 days run into over $1.7 billion, Arce said in a message to the nation. Arce also said 70 people, including 61 police officers, have been injured in the blockades, organized by supporters of former President Evo Morales. “We demand the immediate lifting of all blockade points for the re-establishment of normalcy in our country,”