Eulerian and Hamiltonian Graphs · Challenge problem

Four depots $0,1,2,3$ have roads $01{:}10$, $12{:}3$, $23{:}3$, $03{:}2$, and a direct road $02{:}15$ (five roads total, no others). A crew based at depot $0$ must clear every road and return to $0$, duplicating roads where that is cheapest. What is the minimum total distance the crew must drive?