Please calculate the maximum allowable spread and the respective volume

flow rate for the road given below:

$-$ Residential area street with ADT $<1000$

$-$ Street width is $40$ ft$.$ with $8$ft$.$ service$/$parking lane and $12$ ft$.$ driving lane

$-$ Gutter width is $2$ ft$.$

$-$ Gutter is smooth concrete and asphalt pavement is also smooth texture

$-$ Road cross$-$slope is $3\%$ and gutter slope is $1/12$

$-$ Road longitudinal slope is $2\%$

$-$ Height of the curb is $6$ inches.