But how much? For example, what would be the impact of a 20% reduction in traffic congestion, made possible say by workplaces moving to a 20% remote workforce

But how much? For example, what would be the impact of a 20% reduction in traffic congestion, made possible say by workplaces moving to a 20% remote workforce (or every employee works from home one day per week on average). What if we were to reduce our flights by 10% or 20%? These are things that people can actually envision doing. How much is needed in order to actually help? Maybe only a 5% reduction is needed (one day home in 20)?