Thanks for the feedback, much appreciated!
I tried a few ways to speed it up but this is the quickest I could make it as yet… The output from the vehicle selection is used to filter a pandas dataframe (~270,000 rows), from which the resulting latitude/longitude pairs are used for plotting/sorted into lists for the heat map.
I’ve cached the function which filters the dataframe so I believe it runs better once it’s seen the data, but it wasn’t possible - as far I could tell - to cache the Folium Heatmap function, which might be a factor.
The first plot might take a few seconds itself as there are a lot of points being plotted (270-540k), but like you I’m a sucker for a map and so have left it in :D.
Will try and tidy it up a bit. Thanks again!