Lake Pontchartrain Causeway 23.92 miles Lake Pontchartrain Causeway becomes N CAUSEWAY BLVD. 2.94 miles Stay straight to go onto US-190 W. 1.14 miles Merge onto I-12 E toward SLIDELL. 2.80 miles Take the LA-59 S exit- exit number 65- toward MANDEVILLE. 0.45 miles Merge onto LA-59. 0.7 miles School is on the LEFT