Problem with distance/reach length for bridges

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Problem with distance/reach length for bridges

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I am having a problem with representing the width of a bridge. I have inputted a topographic survey of the upstream (XS 136) and downstream face (XS 135) as standard channel sections; The DS reach length of XS 4.136=15.33 (which is also the width of the bridge).

I added a bridge between these two bounding XS; in the Deck/Roadway Editor I need to input data for Distance (from the US XS to the bridge face) and Width (of bridge). However - since the HEC-RAS manuals advise against using zero distance, I inputted a nominal value of Distance = 0.5m (plus Width = 15.33) - however, this makes the bridge overlap with XS 4.135 as the total distance is now 16.33m – see first image (though this could be resolved by reducing the Width of the bridge e.g. to 14.33m - not ideal though).

I found a workaround by adjusting the DS reach lengths of XS 4.137 by -1m and 4.136 by +1m, thus ‘moving’ XS 136 upstream by 1m – enabling a Distance of 0.5m and Width of 15.33 in the Deck Editor (image on right). As this seems like a slightly messy approach, I would be grateful for feedback on any alternatives. Thanks.