I can sort of understand the meaning of the sentence as someone wants/wishes that the (number of) street lights to increase so that they can feel safe walking at night. But I can't understand what grammar rules were used/observed to form 安心して歩ける
Given the complete sentence above. What is the purpose of having the te-form of する?
Is it used
as a connector to mean "and" e.g. To have peace of mind and to walk?
to mean "while" e.g. have peace of mind while walking?
Maybe there's some grammar construction that I'm missing? Is 歩く even considered to be a motion verb in the same vein as 行く and 来る?