Always reserve a little extra time for your trip. Stretch limousines and buses do not zip around town as your family car does, whatever time it takes you to get to each destination normally, it might be a little longer due to the nature in which a limo transports their passengers, our limousines and party buses always travel at speeds that are about 5-10 MPH under the posted speed limits and often have to take alternate routes to avoid sharp turns, high railroad tracks and other issues that a standard vehicle may be fine with.
Also, time blocks are reserved and entered into the system as set up contracts, oftentimes we have back to back trip reservations where we must go from one client to another. If you think you may need extra time its always a good idea to make your reservation reflect that possible extra time so you know it will be available. The option to extend your trip is only there if there is no other reservation after it. If someone books a reservation right after yours the option to extend your trip may not be an option.