Explanation
Street Level Routing is a feature that calculates travel time between service appointments based on actual road distance and traffic conditions[131]. Default Travel Speed is a setting that defines the average speed of resources when traveling between service appointments[132]. Using Street Level Routing and Default Travel Speed would allow improving travel time accuracy by taking into account real-time road conditions and resource speed. Minimum Grade, Default Operating Hour would not affect travel time accuracy. Minimum Grade is a setting that defines the minimum skill level required for resources to be matched with service appointments[133]. Default Operating Hour is a record that defines the default working hours for resources[134]. Estimated Travel Time, Minimize Travel would not affect travel time accuracy. Estimated Travel Time is a field on the service appointment object that shows the expected travel time for the assigned resource[135]. Minimize Travel is an optimization criterion that prioritizes reducing travel time when scheduling service appointments[136]. Travel Speed Unit, Actual Travel Time would not affect travel time accuracy. Travel Speed Unit is a setting that defines the unit of measurement for travel speed such as miles per hour or kilometers per hour[137]. Actual Travel Time is a field on the service appointment object that shows the actual travel time recorded by the resource[138]. References:
https://help.salesforce.com/s/articleView?id=sf.fs_street_level_routing_overview.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.fs_default_travel_speed.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.fs_minimum_grade.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.fs_default_operating_hours_overview.htm&type=5
https://developer.salesforce.com/docs/atlas.en-us.api.meta/api/sforce_api_objects_serviceappointment_estimated
https://help.salesforce.com/s/articleView?id=sf.fs_scheduling_policies_optimization_criteria.htm&type=5
https://help.salesforce.com/s/articleView?id=sf.fs_travel_speed_unit.htm&type=5
https://developer.salesforce.com/docs/atlas.en-us.api.meta/api/sforce_api_objects_serviceappointment_actualtrav