邮编本身可能含糊不清.如果您在搜索字符串中包含美国"，则可以使用

It could be that the zip code on its own is ambiguous. If you include 'USA' in the search string it works

library(ggmap)

mapdist(from = c("19111, USA"), to = c("19187, USA"))


#         from         to     m    km    miles seconds  minutes     hours
# 1 19111, USA 19187, USA 21420 21.42 13.31039    1976 32.93333 0.5488889

或

library(googleway)

set_key("your_api_key")

google_distance(origins = c("19111, USA"), 
                destinations = c("19187, USA"))

# $destination_addresses
# [1] "Philadelphia, PA 19187, USA"
# 
# $origin_addresses
# [1] "Philadelphia, PA 19111, USA"
# 
# $rows
# elements
# 1 21.4 km, 21420, 33 mins, 1976, 35 mins, 2101, OK
# 
# $status
# [1] "OK"