
    From a set of available delivery routes, each paired with its current traffic congestion score, identify the route ID that has the lowest congestion level. The route-congestion pairs are provided as (route_id, congestion_score) tuples, and the system needs to return the route_id from the tuple that has the minimum congestion_score.
    

    
from operator import itemgetter

def index_minimum(test_list):
    """
    From a set of available delivery routes, each paired with its current traffic congestion score, identify the route ID that has the lowest congestion level. The route-congestion pairs are provided as (route_id, congestion_score) tuples, and the system needs to return the route_id from the tuple that has the minimum congestion_score.
    

    """
from operator import itemgetter

def index_minimum(test_list):
    """
    From a set of available delivery routes, each paired with its current traffic congestion score, identify the route ID that has the lowest congestion level. The route-congestion pairs are provided as (route_id, congestion_score) tuples, and the system needs to return the route_id from the tuple that has the minimum congestion_score.
    

    """
    res = min(test_list, key=itemgetter(1))[0]
    return res