The second term of (4.1) is the max

The second term of (4.1) is the maximum flow that can pass through the pre-signal, and the first term the maximum flow through the signal. For an intersection without turn pockets（N）, the second term is greater than (2.1) by a factor of 1/G. Furthermore, since P, and T , the first term of (4.1) is also greater than (2.1); perhaps considerably so. Thus, for any intersection without turn pockets the tandem system improves capacity. The improvements for typical cases can be quite large. For example, assume that: G=1; l=3;N=1;N=2; and nL = 1, nT = 2, NL = NT = 3 as in Fig. 2a. Then, for the conventional design, (2.1), (2.2), (2.3) yield: q=4; q=2; and q=3/4; and for the tandem design (4.1), (4.2), (4.3) yield: qL = 1/2; qT = 1; and q = 3/2. Thus, capacity is increased by 100%. The same calculations for the partial design of Fig. 2b and c show capacity increases of 71% and 33% respectively. These results are typical. Although it is possible to construct examples with turn pockets where the tandem design would reduce capacity, these examples always involve unreasonably large values of G and/or small values of n/N.