1) Arranging the environment. The student who elopes should be seated away from the door. Use furniture to make the door slightly harder to get to (not saying you should block the door with furniture, but if you use furniture to define the different spaces in your room, you most likely will avoid having a straight shot pathway to the door). You may want to consider placing some window chimes on the door so you can hear when it opens as well...this may not prevent elopement, but will at least speed up your reaction time if it does occur.
2) Visuals. As I mentioned in my last post, keeping visuals by the door or easily accessible around the room can help your student communicate their wants/needs. This may help to increase functional communication and also decrease running. Two visuals I always keep by my door are one for "water" and "bathroom." I have had a few students who don't run often, but when they do, it is for one of these two reasons. Having these visuals by the door is a prompt for them to grab one and bring it over to me or another adult before leaving the classroom. If your student seems to be running out of the room to visit a certain person/classroom or to get access to something, put a picture of the person or object right by the door. Then, when they pick this up and give it to you (you may need to teach them to do this), make sure to honor their request and at least go look for the person or object they are requesting. It may also be helpful to have visuals on the door such as a stop sign or a visual reminder to ask a teacher before leaving the classroom.
3) Increase engagement in the classroom. You want your classroom to have it going on and be the place all your students WANT to be. Find activities that are motivating and related to your students' interests. If your student loves Pokemon or angry birds, make their handwriting worksheets with pictures of these characters and have them write words related to these topics. Find ways to incorporate academics into hands-on activities or games (my kids always loved cooking!). If the function of your student's elopement seems to be for escape, try reducing the amount of demands that are placed on him or her during the day or reducing the amount of work he/she has to complete (these can always be faded back in later...but for now, let's just see if it makes a difference in reducing this dangerous behavior).
5) Schedules. Have a visual schedule to increase the predictability of the day for your student. If you think running needs to be a part of their day, schedule it into their day at regular times.