Yes you can.
You need to add a SMS template to your account with the exact name "Navigate To Job Template".
As a starting point, the standard SMS message template is:
Hello {job.contact_first},
This is a courtesy message to let you know {staff.first} from Company ABC is on the way {and_will_be_arriving_in_approximately_x_minutes}. Please call {staff.mobile} if you are unable to be at the premises at this time.
Note: To specify the approximate arrival time of the tech, use the field {and_will_be_arriving_in_approximately_x_minutes}. It's important to note that estimated time of arrival is not available in all conditions, and so your template should take this into account. If no ETA is currently available, the field will be blank.