Algorithm 1 Gain greedy algorithm
Input:
	G = (V, E): The weighted road graph;
	T: The delay bound;
	B: The budget constraint;
Output:
	c: The placement set of installing c-RSUs;
	w: The placement set of installing w-RSUs;
1:	= ∅, = ∅;
2:	For all i, j ∈ V, initial Dij according to Equation (2);
3:	while the placement cost is not exceed the budget B and ≠ |E| do
4:	for all unselected vi ∈ Vdo
5:	Calc c-RSUs delay-bounded coverage gain gc(i) according to Equation (10);
6:	end for
7:	for all unselected vi ∈ U and vi is with the transmission range of an existing RSU do
8:	Calc w-RSUs delay-bounded coverage gain gw(i) according to Equation (10);
9:	end for
10:	v* = {vi ∣ max{uc(l), uw(k)}, ∀vi ∈ V };
11:	if install a c-RSU and the placement cost is not exceed the budget Bthen
12:	c = c ∪{v*};
13:	else
14:	if install a c-RSU and the placement cost is exceed the budget Bthen
15:	v* = {vi ∣ max{uw(k)}, ∀vi ∈ V };
16:	end if
17:	end if
18:	if install a w-RSU and the placement cost is not exceed the budget Bthen
19:	w = w ∪{v*};
20:	end if
21:	if install a c-RSU or w-RSU and the placement cost is not exceed the budget Bthen
22:	V = V \ {v*};
23:	= ∪ v*;
24:	end if
25:	end while
26:	return c, w