Shipping carriers may have different options where yo need to set a Speed Grade depending on their different services.  For example,  ground delivery versus air delivery.  and the ground delivery with multiple delivery times such as 1-day or 2-day.  The following tutorial allows you to set the Speed Grade for your Carriers in Prestashop 1.5.

How to add or edit a transit time for a carrier in Prestashop 1.5

1. Login to the Administration Panel as an Administrator
2. Hover over the menu bar where it says SHIPPING, and then click on CARRIERS in the drop down menu. This will bring you to a list of the existing carriers
3. Click on the green ADD NEW button or select the Shipping company that you wish modify and select the EDIT icon on the far right of the screen, then go to the CARRIERS section and click on SPEED GRADE as per below:

   
   

4. Click on the blank and type in the Speed Grade information (Integer 0-9).  Remember that "0" equals the longest delay, and "9" represents the shortest delay.
5. Select the green SAVE button in the top right hand corner of the screen in order to save your entry

Setting up SPEED GRADE is handy in that it allows you sort out your carriers.  It allows you to easily judge which shipping method would be best used for a particular customer.  For further information on adding or editing existing Carrier information, please select one of the following:

Overview of how to create a new Carrier in Prestashop 1.5
How to set the Shipping Company Name
How to set the Transit Time
How to add the Speed Grade for a Shipping Company
How to add a Shipping Company's URL
How to select a Continental Zone for Shipping
Selecting the Groups Access for Shipping Carriers
How  to enable Carrier in the Front Office
How to enable Apply regular shipping and additional shipping Costs
How to add regional tax in  addition to shipping costs (United States domestic)
How to include shipping and handling costs in Carrier price
How to  set default Billing- by total price or total weight
How to determine Out-of-range Behavior for Carriers
How to set the Maximum package height for Carriers
How to set the Maximum package width for Carriers
How to set the Maximum package depth for Carriers
How to set the Maximum package weight for Carriers