Use of a single LineString to display two data fields
I have a recurring problem for which I cannot find an easy solution, whereas I guess there is one.
I have a dataset representing road traffic data at a street level. This dataset is associated with a road network graph, where each edge represents a road and each node represents an intersection. For each edge, I have a shapely LineString object containing the geopgraphic properties of the road.
My goal is to draw a map representing this traffic dataset. I can do that quite easily using geopandas for example, but my problem comes from the fact that most roads, even when bi-directionnal, are represented with a single LineString object, so one of the direction won't be seen as both will be plotted on top of each other.
Would there be a simple way to solve this problem? Ideally, I would like to end up with a plot like this: 
The following snippet use offset_curve to double up a line string, which is I think what you are looking for.
data = np.array([np.linspace(0,10), np.sin(np.linspace(0,10))])
road = shapely.LineString(data.T)
constant = 0.1
big_road = shapely.MultiLineString([road.offset_curve(constant), road.offset_curve(-constant)])
which gives:
from shapely import plotting
plotting.plot_line(big_road)
plt.savefig('example.jpg')
