adds two rl changes

01-introduction.Rmd

@@ -402,7 +402,7 @@ This includes the **mapsf** package (successor of **cartography**) [@giraud_maps
 <!-- spatstat?? -->
 
 In late 2021, the planned retirement of **rgdal**, **rgeos** and **maptools** was announced on [the R-sig-Geo mailing list](https://stat.ethz.ch/pipermail/r-sig-geo/2021-September/028760.html) by Roger Bivand.
-This retirement at the end of 2023 have had a large impact on existing workflows applying these packages, but also will influence the packages that depend on **rgdal**, **rgeos** or **maptools**. 
+This retirement at the end of 2023 has had a large impact on existing workflows applying these packages, but also will influence the packages that depend on them. 
 Therefore, Bivand's suggestion was to transition to more modern tools, including **sf** and **terra**, as explained in this book's next chapters.
 
 ## Exercises

13-transport.Rmd

@@ -513,7 +513,7 @@ Routing can be time and memory-consuming, resulting in large objects, due to the
 We will therefore filter the desire lines before calculating routes in this section.
 
 Cycling is most beneficial when it replaces car trips.
-Short (around 5 km, which can be cycled in 15 minutes at a speed of 20 km/hr) have a relatively high probability of being cycled, and the maximum distance increases when trips are made by [electric bike](https://doi.org/10.1016/j.tranpol.2021.11.019) [@lovelace_propensity_2017].
+Short (around 5 km, which can be cycled in 15 minutes at a speed of 20 km/hr) have a relatively high probability of being cycled, and the maximum distance increases when trips are made by electric bike [@lovelace_propensity_2017].
 These considerations inform the following code chunk which filters the desire lines and returns the object `desire_lines_short` representing OD pairs between which many (100+) short (2.5 to 5 km Euclidean distance) trips are driven:
 
 ```{r 13-transport-17, message=FALSE}