network <- model$networks[[1]]
nodeCarType <- network$nodes[[which(sapply(network$nodes, function(item) item$id %in% "car_type"))]]
nodeMilesPerYear <- network$nodes[[which(sapply(network$nodes, function(item) item$id %in% "Miles_per_year"))]]
nodeReliability <- network$nodes[[which(sapply(network$nodes, function(item) item$id %in% "Reliability"))]]
nodeTotalAnnualCost <- network$nodes[[which(sapply(network$nodes, function(item) item$id %in% "total_cost"))]]