Roadway Design Controls and Design Criteria
Roadway Design Controls and Design Criteria
(OP)
For the purpose of a short educational webinar about the AASHTO standards on geometric design I have spent about three hours trying to define clearly what is the difference between design controls and design criteria - the AASHTO way - and I found it is clear in the AASHTO green book - AASHTO have listed all design controls on chapter 2 and later it explained the two main criteria: function of the road (local-collector-arterial-..) and context of the road (urban-rural)
but when I came to different DOT design manuals - I am a little bit confused about the specific meaning (through Montana DOT - Illinois DOT - Mass DOT - Caltrans)
Any help ?
but when I came to different DOT design manuals - I am a little bit confused about the specific meaning (through Montana DOT - Illinois DOT - Mass DOT - Caltrans)
Any help ?





RE: Roadway Design Controls and Design Criteria
Speed Limit:
35 MPH (Local)
45 MPH (Collector)
55 MPH (Arterial)
Your design criteria is the Speed Limit, your design control is your road classification. The recommended values for the criteria are determined by the design control information.
RE: Roadway Design Controls and Design Criteria
RE: Roadway Design Controls and Design Criteria
civilman - your note is somehow related to what Montana DOT follows (for example) - but not other state DOTs
dik - that's nice document and combines a lot of useful information - though different from AASHTO approach - but thank you for the share
RE: Roadway Design Controls and Design Criteria
Dik
RE: Roadway Design Controls and Design Criteria
Revisions to the Controlling Criteria for Design and Documentation for Design Exceptions
RE: Roadway Design Controls and Design Criteria
The use of lane width, and shoulder width as a design control is very confusing -
As per the AASHTO: those are design elements not design controls - I can understand very well that the design speed is a design control, the vehicle characteristics is a design control (minimum turning radii, turning envelopes, acceptable acceleration rates, decceleration rates, ...) , and so on
Traffic volumes and their characteristics are design control (amount of design year volume, accepted level of service, composition,PHF, ...) and the outcome of traffic volume and their characteristics are the ones who determine no of lanes and lane width - so how lane width and shoulder width be a design control ?