After looking on the internet for the last 4 hours, I finally figure it out. You have to put the orderby metadata first, then add a meta_query array to filter through the posts.
$args = array (
'post_type' => 'route',
'meta_key' => 'trip_start_date',
'orderby' => 'meta_value_num',
'order' => 'ASC',
'meta_query' => array(
array(
'meta_key' => 'route_status',
'compare' => '=',
'value' => 'not-yet-launched',
),
),
'posts_per_page' => '9',
);