Problem $4\mathrm{.}3(10$ Points$)$

An undivided multilane highway segment has two $\backslash (11-\backslash$mathrm$\{$ft$\}\backslash )$ wide lanes in the eastbound $($EB$)$ direction with no shoulders and a $\backslash (55-\backslash$mathrm$\{$mph$\}\backslash )$ speed limit$.$ This highway segment has $40$ access points on a $1\mathrm{.}25$ mile, $\backslash (2\mathrm{.}5\backslash \%\backslash )$ upgrade. During the highest $15$ minutes of traffic flow within the peak hour, there are $755$ vehicles and $\backslash (12\backslash \%\backslash )$ of these are heavy vehicles with a $\backslash (70\backslash \%/30\backslash \%\backslash )$ mix of single$-$unit trucks and tractor$-$trailer trucks.

Determine the $($i$)$ estimated speed, $($ii$)$ density, and $($iii$)$ LOS of this upgrade?