Thai/lao Bridge Opening Times (mukdahan)

I need to meet some people coming from Savannakhet to Mukdahan over the bridge. I wonder if someone knows what time the bridge closes? I heard 10pm, with the last bus being at 7pm. If this is the case how can they get over the bridge after 7pm given that apparently it isn't permitted to to walk?

It would be very helpful if someone could give some information about this.

Thanks