precentage split & precentage passing

[tsli001]

Hi guys:

Can someone tell me what is corresponding relation between the percentage split & percentage passing. I know they are two different things but do they actually got relation cause it look likes HCM is putting them together

tsli

 

[natee_dj]

Hi guys:
Can someone tell me what is corresponding relation between the percentage split & percentage passing. I know they are two different things but do they actually got relation cause it look likes HCM is putting them together

tsli

Are you asking about no passing zones and directional split? If so, both of these factors affect the flow rate on a two-lane highway (Ch. 12 & 20) and the final product determining LOS which in this case would be the Percent Time-Spent Following. Look at the formula on page 20-9 and 20-10 to see what I'm talking about. Exh. 20-12 shows the relationship btwn the two. No Passing Zone % is how much percentage of the analyzed length in which passing is prohibited (Pg.12-17) and the directional split is just the percentage of the two-way flow rate expressed in one direction meaning taking a two-way flow rate and making it into a one way directional volume that has the highest flow rate. So the bottom line is that since you're trying to solve for the PTSF, and since the no passing zones causes faster moving cars to follow behind the car in front of them because they can't pass, and also you have the directional split flow rate in that direction you're traveling, you get a relationship between the two. Well, hope I explained it ok... anyone can feel free to fill in...

Hope that helps....