In relation to the schedule? Assuming this is what you mean, and if there was another job scheduled after that the tech is then running late to, the tech would be notified that there is another job they are scheduled for that they are running up against. It really just comes down to an established operating procedures for your organization. The tech can either notify the next client that they are running late (via phone/sms/email template), or can notify the admin. Most opt for the later option, particularly if the tech will be more then 30 minutes late to their next session, as they are usually better suited to either contact the client to notify/reschedule, or reallocate staff to cover.
In short, other then notifying the staff member that there is another Job that they should be starting to make their way to, there is nothing that ServiceM8 automatically does in this case, and simply provides tools to someone to remedy.