<p>sorry, I forgot you said summer. The x173 doesnt run in the summer (the evening shuttle he mentioned). Also, the metra that heads towards the hyde park stations doesnt really connect well to union station so you will already be on CTA to get there (you cant get transfers to metra). If you have a Chicagocard or a chicagocard plus, $2 gets you 3 seperate rides within an hour of each other (most train to train transfers dont count since you only swipe the card once).</p>