Roadway cross-section sheets are read from which part to which part of the sheet?

In the context of reading roadway cross-section sheets, the correct approach is to read from bottom to top. This method makes sense because the bottom portion of the sheet typically displays the existing ground level or subgrade, while the upper sections illustrate the various layers of the roadway, such as the pavement structure and any proposed features above the existing grade. By following this bottom-to-top progression, one can accurately interpret how the proposed roadway will relate to the existing terrain and understand the elevation changes necessary for proper drainage and construction.

Reading in this manner allows for a clear understanding of the vertical relationship between different components of the roadway, which is crucial for planning and executing transportation projects effectively. The other reading directions do not align with the standard practices for interpreting cross-section sheets, as they would fail to reflect the relative positions and elevations of the roadway components accurately.