Fig. 3

Number of FCs accessible by ECs under different travel modes and time constraints. a, b respectively represents the number of accessible FCs under the non-driving and driving modes with a travel time limit of 15 min (inclusive). c, d respectively demonstrates the number of accessible FCs under non-driving and driving modes with a travel time limit of 30 min (inclusive). e manifests the number of accessible FCs under non-driving modes with a travel time limit of 45 min (inclusive)