U.S. Highway Emergency Vehicle Crossing

I am trying to figure out a way to add the Bi-Directional Emergency Vehicle U-Turns that most U.S. Divided highways have. I can make a service road, but it often only wants to make them unidirectional (one way) and I need them to be two way. I am fairly new to OSM so I apologize for a noob question or if this has been asked before and I missed it

Assuming that the service roads are only for emergency vehicles, the basic tags would be

Without a ‘oneway’ tag, it is assumed to be bidirectional.

The editor you are using may present things differently; the oneway tag may be a checkbox that should be unchecked.

+access=no + emergency=yes
otherwise drivers will get dangerous driving directions.

Thank you for your help. I hate being a noob, but I couldn’t find what I was looking for. One other question, how do I make a road end in a cul-de-sac?

Not sure what you mean, never the less, for what it’s worth…
You stop drawing the way at the end , usually with a double click, and the road simply ends there. No special tag is required at the end as the map shows the road terminating at that point.
Some cul-de-sacs end in a turning circle where you add highway=turning_circle to the end node, some cul-de-sacs have a barrier at the end so barrier=? can be added. http://wiki.openstreetmap.org/wiki/Key:barrier
The above Cul-de-sac link shows an example of 2 cul-de-sacs created by a row of bollards. In that example, I would end each side of the road in a separate node for each and also tag a barrier between those 2 end nodes.
I am not aware if you can add one of those signs at the end to warn people that the road ends here - usually black and white striped sign across the road to stop you proceeding further.
You may be able to add a node for a sign at the entry to the road stipulating that it is a ‘no through road’ but I haven’t come across one yet in the osm.
Edit: Just found this … http://wiki.openstreetmap.org/wiki/Key:noexit

It is best to start a new query for a new subject instead of tagging it on the end as you have done here.
…and you are encouraged to ask more queries as they are helpful to other mappers too.