Your situation
You said: the policy is approved, and in practice nothing changes.
You said: people get round it, or comply only on paper.
You said: it works for some, but not for those you need most.
You said: you have tried all sorts, and the target group does not move.
And it is about residents. They do not read your policy. They meet it at one moment in their day. That moment is what you design.
And it is about businesses. There too a person decides, under time pressure, with what the sector does as the benchmark.
And it is about your own front-line workers. Policy is made at the counter. What the system and the team lead make easy beats the policy paper.
A decision is not yet behaviour. The whole of practice sits in between.
The policy is correct and approved. And the target group has never seen it. People rarely change their behaviour because they know something. They change because their environment changes. And that environment is the form, the front-line worker, the default option.
Tomorrow, find the exact moment when the behaviour you want has to happen. Look at what the target group meets there. Translating policy into moments like that is what you learn in two days, with a method that fits every stage of the policy cycle.
They are not against your policy. The old behaviour is easier and safer.
Whoever gets round it or complies only on paper takes the path of least effort and least risk. Policy counts on people who plan, persist and resist temptation. In 2017 the Dutch Scientific Council for Government Policy (WRR) showed in its report on the capacity to act that this falls short for large groups. Enforcement makes avoiding more expensive. It does not make the behaviour you want any easier.
Tomorrow, look at what complying concretely costs the target group in time, money and hassle. Remove one step.
Those who already wanted to, move. Those you need are in a different situation.
Information and arguments reach the people who were already motivated. The group your policy is meant for has less time, less trust and different norms in the street. A rule that goes against the visible norm usually loses.
Tomorrow, pick one person from that group. Follow their day up to the moment your policy touches them. That is how you get to know the target group from the outside in.
Every instrument rested on the same assumption. Test it first.
Information, rules, subsidies: every instrument assumes something about why the target group does not do what you want. If that assumption is wrong, every instrument fails, however well it is run. And every intervention moves the problem somewhere else. Maybe it is not a lack of knowledge but effort. Maybe not unwillingness but a social norm.
Tomorrow, write down the assumption under your current policy in one sentence. Ask yourself what the evidence for it is. Then replace that assumption with a diagnosis.