LADOTD deceleration lane requirements in Louisiana LA

[YTC]

Have anybody done any projects in Louisiana where a deceleration lane was required? I'm trying to find out what warrants a decel lane (into a commercial area) and what the LaDOTD design and permitting requirements are. Information on their website is somewhat limited. Thanks in advance!

CE in GA

 

[TrafficDesigner]

I am not familiar with LaDOTD but usually what warrents a deceleration lane into a site is the amount of traffic that will be generated by that site to make the right turn.

This information would be provided in the Traffic Study. The study should tell you how many vehicles will make the right turn into the site duing AM and PM peak hours. Out here a general rule of thumb is if 100 or more cars will make the right turn than you need to install it.

The queue length should also be discussed in the Traffic Study. That will give the length of the lane, not including the taper to transition into the lane.

For example, if 150 vehicles will turn right during the peak hour, then a general rule of thumb is you will need a 150' long turn queue. The taper transition should be a standard used by your DOT. This is dependent on the speed limit of the road.