Webster delay model is applicable to signal controlled intersections only while HCM provides delay equations almost for every type of interrupted facility. Be specific which type of problem you are working on. Both of these models do not give correct results under mixed traffic conditions like prevailing in India and other developing nations.

Thanks @ Satish Chandra sir.

But can you tell me that under what conditions we use or compare with HCM. I am not able to clearly understand it. Thanks in advance.

HCM method is based on the concept of lane groups. Lane group is a lane (or lanes) serving one or more than one type of movement(s) in the approach. It means all lanes in the approach can be put in to maximum of three lane groups, one for left, one for through and one for right turning vehicles. Each lane group can have one or more than one lane in it depending upon the total number of lanes in the approach. Saturation flow and delay are calculated for each lane group separately.

Webster Method assumes flow in the total approach width, it is not based on the lanes, but still assumes arrival rate to be random in each approach.

I hope it answers your query.

Thanks sir once again.

Sorry to bother you. But can you suggest if we are working on signalized intersection with in SUMO and compare our algorithm with that of Webster. Do we need to compare it with HCM also. If no, what justification we need to give. Is it same as you specified earlier. Thank in advance.

Dear Vinita,

It would help if you could better describe the actual application you have in mind. For instance, is it in saturated intersections?

Also, are the intersections instrumented at all? Are they managed in any way? Can you collect data on the interesection approaches and movements?

Your answer would help to better understand how to assist you.

Thanks @ Yorgos J. Stephanedes  sir. I want to simulate the intersections in a developing country like India. I am trying to develop some algorithms and want to compare it with existing delay functions. 

Thanks for your reply.

No, you need not compare it with HCM for simple reason. The traffic is of mixed type and lane discipline is extremely poor and hence considering the total width of the approach for a particular movement (as in the case of Webster's method) is more appropriate.

Thanks @Satish Chandra sir.

Dear Vinita..for the intersection to be analysed..could you please inform me what is the value of V/C value ..in order to be able to answer you in detail..regards 

I agree with Dr Amjad,you must specify V/C ratio ???