Traffic Flow - Junction, Delay, Webster, Greatest Upper Bound

[MidnightR]

[PLAIN]http://img96.imageshack.us/img96/7816/12530747.jpg

Hopefully this will post successfully...

Erm its the first part I'm not sure on, after that it's easy. I'm just not understanding the wording.

I need to work out the effective green time during the cycle

 

[MidnightR]

I believe since q = 0.7 then g > or = 0.35c what would this make the greatest lower bound? g = 0.35c?

 

[MidnightR]

Think I got it,

c=? q=0.7 s=2 therefore

g/c <=1
0.35c/g <= 1

therefore

g <= c <= g/0.35

we know c = g +10 so g= 10-c & sub in

c-10 <= c <= (c-10)/0.35

so assuming c is positive then

c >= 200/13 so take greatest lower bound = 200/13

however I'm still not sure that c = g+10 rather than c=2g+10