7 thoughts on “Highway design

  1. Quite easily why it was done that way. The slope required to meet the height requirements over the track would be to steep if it was done straight. Also the intersection probably would need to be redesigned. Thus it was probably cheaper and traffic would not have to be interrupted during construction

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  2. My initial guess has to do with the steepness of the grade that would be needed. To connect the two directly could require demolishing a large portion of the already existing road, assume doing so would still make the grade issue fixable.

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  3. It’s pretty obviously to raise traffic up and over the train tracks without making the grade too steep.

    I’m glad roadways are designed by engineers and not idiots on the internet.

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  4. Exactly right. The grade would be too steep. It also functions nicely as a traffic absorption buffer if that intersection gets backed up.

    A good example of this grade issue is the Coronado Bridge that crosses San Diego Bay. The bridge is not a straight shot across the bay at it’s narrowest point. Instead, it is a long curved track to the south. The reason is that the bridge has to be high enough for the Navy and cargo ships to pass under (200 feet). And to get that altitude with a reasonable grade requires distance (1 mile).

    http://www.trbimg.com/img-57ba5893/turbine/sdut-the-san-diego-coronado-bridge-20160821/650/650×366

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