これを試してください
$sql = "SELECT * FROM drives WHERE ddest = '{$trimmed}' AND 'leave_date' >= NOW() LIKE '%$trimmed%' ORDER BY timeago DESC";
それ以外の場合、
$sql = "SELECT * FROM drives WHERE ddest = '{$trimmed}' AND 'leave_date' >= DATE_FORMAT(CURDATE(), '%m/%d/%Y') LIKE '%$trimmed%' ORDER BY timeago DESC";