The city, having $162$ thousand inhabitants, has requested to evaluate its solids waste collection

system.

Determine:

i$)$ mean time per collection stop plus the mean time to reach the next stop,

ii$)$ number of pickup locations per load

iii$)$ minimum number of trucks the city must own.

Consider the following data:

a$)$ Average truck capacity $=18$ m$3$

b$)$ Average observed compaction ratio $=3\mathrm{.}28$

c$)$ Crew size $=2$ persons

d$)$ Number of pickups $=1/$week $($no rear$-$of$-$house service$)$

e$)$ Average number of residences per stop$=2\mathrm{.}5$

f$)$ Average uncompact density $=122$ kg$/$m$3$

g$)$ Average transport time to disposal site including delay and dumping $=1\mathrm{.}5$ h$/$trip

h$)$ Average number of trips to disposal site $=2/$day

i$)$ Rest breaks $=2$ of $15$ min

j$)$ Average maintenance downtime $=36$ min$/$day

k$)$ Average workday $=8$ hours

l$)$ Average percentage of truck out of service for majority repairs $=15\%$

m$)$ Average number of cans per stop $=2\mathrm{.}5/$wk at $0\mathrm{.}0911$ m$3$

$/$can