10 minutes a day on a commute to work and back is significant and, if you drop down a couple mph, is low risk. That’s almost an extra hour a week without giving up any valuable activity.
I could only see the cost/benefit looking not worthwhile if you already have a lot of free time. An adult commuting 90 minutes a day might only have 2-4 hours of free time per day during the workweek.
Yes, this should also be considered although the rarity of a crash where the consequences will take longer to deal with means it isn’t meaningfully part of the time benefit calculation. Sorry to speak morbidly.
The effect also depends on the natural speed at which traffic flows and how the extra time is spent, as fatigue also increases crash risk.
I could only see the cost/benefit looking not worthwhile if you already have a lot of free time. An adult commuting 90 minutes a day might only have 2-4 hours of free time per day during the workweek.