The original creator of this type of train track offers just such a support piece.[0]  You can also 3D print your own supports![1]<p>[0] <a href="http:&#x2F;&#x2F;i.ebayimg.com&#x2F;00&#x2F;s&#x2F;MTIwMFgxNjAw&#x2F;z&#x2F;DAUAAOSwGvhT3ny3&#x2F;$_35.JPG" rel="nofollow">http:&#x2F;&#x2F;i.ebayimg.com&#x2F;00&#x2F;s&#x2F;MTIwMFgxNjAw&#x2F;z&#x2F;DAUAAOSwGvhT3ny3&#x2F;$_...</a><p>[1] <a href="http:&#x2F;&#x2F;www.thingiverse.com&#x2F;thing:110221" rel="nofollow">http:&#x2F;&#x2F;www.thingiverse.com&#x2F;thing:110221</a>