1. People outside are inherently low risk. Risk of transmission outside is low.
2. Lots of evidence that vaccination reduces risk of transmission quite significantly. So risk of transmission from vaccinated people is lower.
Put 1 and 2 together and that is why.
Plus if only passing them on the cycle track then any risk is going to be more or less zero anyway.
Still lacking in consideration, regardless. They were in the bloody way. Bloody hi vis noobs...