Skip to main content

In this exercise we’re going to be specifying profile design criteria currently I’m in the 08 profile Dash 4A drawing which is located in your tutorials folder or you can find the exercise file down below within the description on YouTube in the upcoming videos we’re going to be getting into laying out our proposed Road profile with certain design criteria for example for the curves such as the SAG of a curve or the crest of a curve we want certain design criteria to be met now for Road design criteria you need a certain amount of horizontal distance in order to achieve the proper K value for a vertical curve if you were to go to Google and ask what is K and Road profile it says here the K value is the horizontal distance required to achieve a one percent change in the slope of a vertical curve it shows here k equals L divided by a where L is the length of a curve and a is the absolute value of difference in the grades K factors for various anticipated operating speeds are given in the ashto green book we’ll start by specifying some design criteria when we actually create a row profile we’ll do that by going to our create design panel then select this profile drop down select profile creation tools and then select our profile we want to give it a name we want to call this main road

and for the general tab we’ll leave this on the design profile but I don’t want a label set specified I want to go then to the design criteria and I want to use criteria based design you’ll notice that we get this little check box right here and we have some information if we click on this button and this gets into some of our ashto related information now you’ll notice that all of our XML information for our roadway design standards are in metric I want to change that I want to change that to Imperial by going up one folder then go into imperial and I want to select the 2018 roadway design standards I’m going to go ahead and select open then you’ll see within the default criteria our minimum K table is set to our ashto 2018 design standard next I want to make sure that this check box is checked to use design check set I’m going to create a brand new one by selecting this drop down then select create new make sure you’re on the design checks Tab and under type I want to specify a curve then as a check I want to make sure that all of my curve lengths are greater than or equal to 30 feet I’m going to go ahead and add this then I’m going to select another curve check that I want to make sure that the curve length for this is greater than or equal to 60 as well I’m going to click add but for the apply to for the 30 I’m going to change that to Crest curves only and for the 60s

this is going to be sag curves only I’m going to select apply then okay then okay once again and then up Pops our profile layout tools toolbar in the upcoming videos we’re going to be actually laying out our row profile however this is how you specify design criteria for your road within civil 3D