https://phys.org/news/2018-06-bike-lanes-stress-riders.html

To measure the impact of protected bike lanes in Edmonton, which cost $7.5 million to build, Cabral began by classifying roadways into four categories based on how stressful they are for cyclists to navigate using the Level of Traffic Stress (LTS) framework. LTS 4 is the highest stress level and includes any cycling situation regardless of traffic volume and speed limit. The target level for a relatively safe and stress-free citywide cycling network is LTS 2.

"There is always a limit to how much traffic a cyclist can deal with," said Cabral.