Lane between Girders: How a common lane is defined w.r.t girders?

[IJR]

Pals

I have a 4-lane bridge, but there are actually 3 girders supporting the 4 lanes.

So girders share lanes.

Problem is, for the first shared lane, I start defining the lane by associating with the frame elements of the first girder using an accentricity of the centreline of lane to centreline of girder.

Then for the same shared lane, I have to associate it with frame elements of the second girder using an appropriate eccentrity.

So far so good.

By the time I am finished with the first girder, the lane shows OK on screen graphics

But when I start adding the second girder, the lane shows skewed and messed up.

What could be my fault? Some order required?

Respects

IJR