How to deal with problem when a ramp to ramp flow exists???

[sashi34u]

In a particular question related to the weaving, merge and diverge analysis it is given that a ramp to ramp flow of 200 veh/h exists.

It is a 3 lane highway section with free way flow of 3200 veh/h. the section has 2 ramps. The first one is an on ramp with a ramp flow of 600 veh/h. The second ramp is an off ramp with a flow of 75o veh/h.

The problem suggests that an auxillary lane is brought in between the on and off ramps, thus converting it into a weaving section.

Now my doubt is
1) Should I consider inner weaving volumes(Vw1, Vw2) as
Vw1=750veh/h and Vw2=600Veh/h

(or)

2) Should i consider the inner volumes as
Vw1=(750-200)=550 Veh/h
Vw2=(600-200)=400 Veh/h
I had deducted 200 from the volumes as it is ramp to ramp flow.

Can anyone clear my doubt?

 

[teeman]

Your second calculation appears to be correct.
The ramp to ramp flow is 200 non-weaving vehicles.
The on-ramp to freeway weaving volume is the on-ramp volume minus the non-weaving traffic (600-200=400)
The freeway to ramp weave is the off-ramp volume minus the non-weaving traffic from the upstream ramp (750-200=550)
Vw1 is the higher weaving volume

 

[sashi34u]

Hi teeman,

Yes what you said is correct. tyhe second part is right.
I got to know about it from my professor.



Thanks for responding.