From Cab Grid Pro version 5 there is a hidden feature that allows the order of certain elements to be defined. These include the order of places in the origin and destination drop-down lists, and the order that vehicles are chosen for journeys.
https://your-wordpress-site.com/wp-admin/admin.php?page=cab-grid-pro-areas&priority=show
Areas
Areas are sorted within origin and destination drop-down menus alphabetically by default. If areas are grouped, the groups are also sorted alphabetically. This means that either areas or groups sort order can be manipulated by prefixing a digit to the label. For example, ‘1. group name’, ‘2. another group’ When the priority value is set, alphabetical sorting is overridden, and each list is sorted from lowest to highest priority (ascending). Other filters still apply, for example groups. The Cab Grid Pro price TABLE shortcode will also order places based on priority (if set).
Vehicles
In modes other than VEHICLE, the vehicle for a journey is selected based on customer input. The number of passengers, luggage, time or tickets determines which vehicle – and hence price – is selected for a given journey. In some cases, there may be two or more vehicles with the same capacities and unit rate. If there is no way to distinguish between vehicles, the vehicle name field is used, with the first vehicle alphabetically being selected. When the priority value is set, if vehicles with matching capacities exist, the priority value determines which vehicle is selected. The vehicle with the lowest priority value will be chosen, and the price for the journey in that vehicle will be returned to the customer. Note: vehicle priority requires Cab Grid Pro v5.0.2