Google Maps allows users to find directions between locations.
The Google Maps Directions API is a service available to developers that calculates directions between locations, and outputs the data as JSON.
The googleway package allows R users to find a route between two locations, and decode the ‘polyline’ sections of the outputs, into a data.frame
of latitude and longitude coordinates that represent all the waypoints of the directions.
Searching Google Maps for directions from Melbourne to Sydney generates the route:
Melbourne to Sydney
The same query using the developers API generates the data in JSON
Melbourne to Sydney JSON
This result can be returned using the get_route()
function.
Note you can return the output as JSON or a data.frame.
library(googleway)
## you will need a valid Google Directions Developers API key
df <- get_route(origin = "Melbourne, Australia",
destination = "Sydney, Australia",
key = key,
mode = "driving",
output_format = "data.frame")
The data used to draw the route is the overview_polyline
Melbourne to Sydney polyline
whichc is located in df$routes$overview_polyline$points
.
df$routes$overview_polyline$points
# [1] "rqxeF_cxsZgr@xmCekBhMunGnWc_Ank@vBpyCqjAfbAqmBjXydAe{AoF{oEgTqjGur@ch@qfAhUuiCww@}kEtOepAtdD{dDf~BsgIuj@}tHi{C{bGg{@{rGsmG_bDbW{wCuTyiBajBytF_oAyaI}K}bEkqA{jDg^epJmbB{gC}v@i~D`@gkGmJ_kEojD_O{`FqvCetE}bGgbDm_BqpD}pEqdGiaBo{FglEg_Su~CegHw`Cm`Hv[mxFwaAisAklCuUgzAqmCalJajLqfDedHgyC_yHibCizK~Xo_DuqAojDshAeaEpg@g`Dy|DgtNswBcgDiaAgEqgBozB{jEejQ}p@ckIc~HmvFkgAsfGmjCcaJwwD}~AycCrx@skCwUqwN{yKygH}nF_qAgyOep@slIehDcmDieDkoEiuCg|LrKo~Eb}Bw{Ef^klG_AgdFqvAaxBgoDeqBwoDypEeiFkjBa|Ks}@gr@c}IkE_qEqo@syCgG{iEazAmeBmeCqvA}rCq_AixEemHszB_SisB}mEgeEenCqeDab@iwAmZg^guB}cCk_F_iAmkGsu@abDsoBylBk`Bm_CsfD{jFgrAerB{gDkw@{|EacB_jDmmAsjC{yBsyFaqFqfEi_Ei~C{yAmwFt{B{fBwKql@onBmtCq`IomFmdGueD_kDssAwsCyqDkx@e\\kwEyUstC}uAe|Ac|BakGpGkfGuc@qnDguBatBot@}kD_pBmmCkdAgkB}jBaIyoC}xAexHka@cz@ahCcfCayBqvBgtBsuDxb@yiDe{Ikt@c{DwhBydEynDojCapAq}AuAksBxPk{EgPgkJ{gA}tGsJezKbcAcdK__@uuBn_AcuGsjDwvC_|AwbE}~@wnErZ{nGr_@stEjbDakFf_@clDmKkwBbpAi_DlgA{lArLukCBukJol@w~DfCcpBwnAghCweA}{EmyAgaEbNybGeV}kCtjAq{EveBwuHlb@gyIg\\gmEhBw{G{dAmpHp_@a|MsnCcuGy~@agIe@e`KkoA}lBspBs^}sAmgIdpAumE{Y_|Oe|CioKouFwuIqnCmlDoHamBiuAgnDqp@yqIkmEqaIozAohAykDymA{uEgiE}fFehBgnCgrGmwCkiLurBkhL{jHcrGs}GkhFwpDezGgjEe_EsoBmm@g}KimLizEgbA{~DwfCwvFmhBuvBy~DsqCicBatC{z@mlCkkDoaDw_BagA}|Bii@kgCpj@}{E}b@cuJxQwkK}j@exF`UanFzM{fFumB}fCirHoTml@CoAh`A"
Having retreived the polyline, we can now decode it
polyline <- "rqxeF_cxsZgr@xmCekBhMunGnWc_Ank@vBpyCqjAfbAqmBjXydAe{AoF{oEgTqjGur@ch@qfAhUuiCww@}kEtOepAtdD{dDf~BsgIuj@}tHi{C{bGg{@{rGsmG_bDbW{wCuTyiBajBytF_oAyaI}K}bEkqA{jDg^epJmbB{gC}v@i~D`@gkGmJ_kEojD_O{`FqvCetE}bGgbDm_BqpD}pEqdGiaBo{FglEg_Su~CegHw`Cm`Hv[mxFwaAisAklCuUgzAqmCalJajLqfDedHgyC_yHibCizK~Xo_DuqAojDshAeaEpg@g`Dy|DgtNswBcgDiaAgEqgBozB{jEejQ}p@ckIc~HmvFkgAsfGmjCcaJwwD}~AycCrx@skCwUqwN{yKygH}nF_qAgyOep@slIehDcmDieDkoEiuCg|LrKo~Eb}Bw{Ef^klG_AgdFqvAaxBgoDeqBwoDypEeiFkjBa|Ks}@gr@c}IkE_qEqo@syCgG{iEazAmeBmeCqvA}rCq_AixEemHszB_SisB}mEgeEenCqeDab@iwAmZg^guB}cCk_F_iAmkGsu@abDsoBylBk`Bm_CsfD{jFgrAerB{gDkw@{|EacB_jDmmAsjC{yBsyFaqFqfEi_Ei~C{yAmwFt{B{fBwKql@onBmtCq`IomFmdGueD_kDssAwsCyqDkx@e\\kwEyUstC}uAe|Ac|BakGpGkfGuc@qnDguBatBot@}kD_pBmmCkdAgkB}jBaIyoC}xAexHka@cz@ahCcfCayBqvBgtBsuDxb@yiDe{Ikt@c{DwhBydEynDojCapAq}AuAksBxPk{EgPgkJ{gA}tGsJezKbcAcdK__@uuBn_AcuGsjDwvC_|AwbE}~@wnErZ{nGr_@stEjbDakFf_@clDmKkwBbpAi_DlgA{lArLukCBukJol@w~DfCcpBwnAghCweA}{EmyAgaEbNybGeV}kCtjAq{EveBwuHlb@gyIg\\gmEhBw{G{dAmpHp_@a|MsnCcuGy~@agIe@e`KkoA}lBspBs^}sAmgIdpAumE{Y_|Oe|CioKouFwuIqnCmlDoHamBiuAgnDqp@yqIkmEqaIozAohAykDymA{uEgiE}fFehBgnCgrGmwCkiLurBkhL{jHcrGs}GkhFwpDezGgjEe_EsoBmm@g}KimLizEgbA{~DwfCwvFmhBuvBy~DsqCicBatC{z@mlCkkDoaDw_BagA}|Bii@kgCpj@}{E}b@cuJxQwkK}j@exF`UanFzM{fFumB}fCirHoTml@CoAh`A"
library(googleway)
df <- decode_pl(polyline)
head(df)
## lat lon
## 1 -37.81418 144.9632
## 2 -37.80598 144.9404
## 3 -37.78867 144.9380
## 4 -37.74520 144.9341
## 5 -37.73494 144.9270
## 6 -37.73554 144.9023
# library(leaflet)
#
# leaflet(df) %>%
# addTiles() %>%
# addPolylines(lat = ~lat, lng = ~lon)