如果您使用sf 包，这很容易：
#install.packages("sf)
library(sf)
# I have downloaded the Overpass query as a GeoJSON file
route <- st_read("export.geojson")
结果是一个数据框，其中每个特征都表示为一行，因此您可以对其进行子集化（即 route[1:3,]）以仅提取您感兴趣的特征。
特征属性存储为列，因此您也可以轻松选择其中的一个子集。
就是这样！
让我们看看你的具体情况。
有 89 个功能：
nrow(route)
[1] 89
具有 12 个属性（最后一列，编号 13，出现在所有 sf 对象中并保存几何数据）
names(route)
[1] "id" "X.id" "from"
[4] "name" "network" "public_transport.version"
[7] "ref" "route" "source"
[10] "to" "type" "X.relations"
[13] "geometry"
看起来像这样：
plot(route)
（只有前十个属性显示为plot()，除非您使用max.plot = 10）
检查数据框，您可以看到有两个折线要素和 87 个点要素 - 运输路线和运输站，我假设。
summary(route$geometry)
MULTILINESTRING POINT epsg:4326 +proj=long...
2 87 0 0
前两行包含线，其余代表点。
head(route)
Simple feature collection with 6 features and 12 fields
geometry type: GEOMETRY
dimension: XY
bbox: xmin: 20.89744 ymin: 52.21596 xmax: 21.10796 ymax: 52.25929
epsg (SRID): 4326
proj4string: +proj=longlat +datum=WGS84 +no_defs
id X.id from
1 relation/4254149 relation/4254149 PKP Olszynka Grochowska
2 relation/4254150 relation/4254150 Stare Bemowo
3 node/32920674 node/32920674 <NA>
4 node/209094035 node/209094035 <NA>
5 node/251880529 node/251880529 <NA>
6 node/302874515 node/302874515 <NA>
name network public_transport.version ref route
1 Bus 523: PKP Olszynka Grochowska => Stare Bemowo ZTM Warszawa 2 523 bus
2 Bus 523: Stare Bemowo => PKP Olszynka Grochowska ZTM Warszawa 2 523 bus
3 <NA> <NA> <NA> <NA> <NA>
4 <NA> <NA> <NA> <NA> <NA>
5 <NA> <NA> <NA> <NA> <NA>
6 <NA> <NA> <NA> <NA> <NA>
source to type
1 Rozkład jazdy ZTM Warszawa, trasa wygenerowana przez bot Stare Bemowo route
2 Rozkład jazdy ZTM Warszawa, trasa wygenerowana przez bot PKP Olszynka Grochowska route
3 <NA> <NA> <NA>
4 <NA> <NA> <NA>
5 <NA> <NA> <NA>
6 <NA> <NA> <NA>
X.relations
1 <NA>
2 <NA>
3 [ { "role": "stop", "rel": 4254149, "reltags": { "from": "PKP Olszynka Grochowska", "name": "Bus 523: PKP Olszynka Grochowska => Stare Bemowo", "network": "ZTM Warszawa", "public_transport:version": "2", "ref": "523", "route": "bus", "source": "Rozkład jazdy ZTM Warszawa, trasa wygenerowana przez bot", "to": "Stare Bemowo", "type": "route" } } ]
4 [ { "role": "stop", "rel": 4254150, "reltags": { "from": "Stare Bemowo", "name": "Bus 523: Stare Bemowo => PKP Olszynka Grochowska", "network": "ZTM Warszawa", "public_transport:version": "2", "ref": "523", "route": "bus", "source": "Rozkład jazdy ZTM Warszawa, trasa wygenerowana przez bot", "to": "PKP Olszynka Grochowska", "type": "route" } } ]
5 [ { "role": "stop", "rel": 4254150, "reltags": { "from": "Stare Bemowo", "name": "Bus 523: Stare Bemowo => PKP Olszynka Grochowska", "network": "ZTM Warszawa", "public_transport:version": "2", "ref": "523", "route": "bus", "source": "Rozkład jazdy ZTM Warszawa, trasa wygenerowana przez bot", "to": "PKP Olszynka Grochowska", "type": "route" } } ]
6 [ { "role": "stop", "rel": 4254150, "reltags": { "from": "Stare Bemowo", "name": "Bus 523: Stare Bemowo => PKP Olszynka Grochowska", "network": "ZTM Warszawa", "public_transport:version": "2", "ref": "523", "route": "bus", "source": "Rozkład jazdy ZTM Warszawa, trasa wygenerowana przez bot", "to": "PKP Olszynka Grochowska", "type": "route" } } ]
geometry
1 MULTILINESTRING ((21.10695 ...
2 MULTILINESTRING ((20.89804 ...
3 POINT (21.07858 52.23575)
4 POINT (21.08457 52.24583)
5 POINT (21.07847 52.23509)
6 POINT (21.08454 52.24331)
如果您只想要第一个功能，您可以相应地简单地对数据框进行子集化：
myfeature <- route[1,]
您可能还需要一组功能，例如所有线条。在这里很容易选择它们，因为我们知道它们在前两行：
route_lines <- route[1:2,]
plot(route_lines)
或要点：
route_stations <- route[3:89,]
plot(route_stations)
最后，如果您想保存提取的特征，只需执行以下操作：
st_write(route_stations, "route_stations.geojson")
有关sf 提供的真正酷功能的更多信息，请参阅https://cran.r-project.org/web/packages/sf/vignettes/sf1.html。