$system_alert = new WP_Query( array(
	'post_type' => 'alert',
	'posts_per_page' 	=> 1,
	'meta_query' => array(
		array(
			'key' 	  => 'affected_routes',
			'value'   => 'all_routes',
			'compare' => 'LIKE',
		)
	)
));

$more_system_alerts = new WP_Query( array(
	'post_type' => 'alert',
	'posts_per_page' 	=> 2,
	'offset' => 1,
	   'meta_query' => array(
		   array(
			   'key' 	  => 'affected_routes',
			   'value'   => 'all_routes',
			'compare' => 'LIKE',
		   )
	)
));