
    Given a list of potential delivery routes where each route contains a location ID and its estimated travel time considering current traffic and weather conditions, determine the location ID of the route with the shortest travel time. The travel time is measured in minutes, and each location ID is a unique identifier for a delivery destination.
    

    
from operator import itemgetter

def index_minimum(test_list):
    """
    Given a list of potential delivery routes where each route contains a location ID and its estimated travel time considering current traffic and weather conditions, determine the location ID of the route with the shortest travel time. The travel time is measured in minutes, and each location ID is a unique identifier for a delivery destination.
    

    """
from operator import itemgetter

def index_minimum(test_list):
    """
    Given a list of potential delivery routes where each route contains a location ID and its estimated travel time considering current traffic and weather conditions, determine the location ID of the route with the shortest travel time. The travel time is measured in minutes, and each location ID is a unique identifier for a delivery destination.
    

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