The Cruz Roja said 800 of its workers and volunteers will staff 35 aid stations for pilgrims starting at 8 a.m. Saturday.
That is when the greatest flow of romeros, as they are called, is expected to begin.
The destination for the pilgrims is the Basílica Nuestra Señora de los Ángeles in Cartago. Most of the aid stations are set up between San José and Cartago because the bulk of the pilgrims travel that route.
Being a pilgrim is not without pain in many cases. Leg cramps, blisters and pulled muscles are frequently complaints.
Some 10 of the aid stations will have ambulances on standby, the rescue agency said.
Last weekend the Cruz Roja helped 168 early bird pilgrims, the agency said. Four of these went to hospitals.
Traffic police will be on duty starting tonight at 9 o’clock on the Carretera Florencio del Castillo. Diverting traffic will begin Friday, the Policía de Tránsito said.