classSaleTransportOrder(models.Model):

         _inherit = 'sale.order'

          transport_id = fields.Many2one('transport.management', string="Transport Via")
         defaction_confirm(self):

         res =  super(SaleTransportOrder,  self).action_confirm()

          for rec in self:

        rec.picking_ids.write({'transport_id':rec.transport_id.id})

       returnres

classStockpicking(models.Model):

        _inherit = "stock.picking"

          transport_id=fields.Many2one("transport.management",string="TransportVia",tracking=True,readonly=True)

route_id = fields.Many2one("transport.routes", string="Route",tracking=True,)

i wont to add domain fields transport_id to route_id