What verbs collocate with policy?
Make a policy? Develop a policy?
The government should make a a policy to reduce the number of cars.
Does this sound correct?
There are many verbs that can logically take policy as an object. The meaning will be different in each case.
One might set out a policy. This means to explain, preferably thoroughly and clearly, what the policy is. It can apply to a proposed policy as well as one that is actually being put into force. In the case of organisations that have policies of primarily rhetorical value rather than practical, such as a political party (especially one not in control of government), it may be the most formal thing done with a policy. Set forth would be largely synonymous in this context. For the meaning of explanation, you could also just use explain.
One might formulate or develop a policy. This refers to the process of coming up with the policy, and may involve several drafts, consultations and so on.
One might adopt, establish, or promulgate a policy. This refers to putting a policy into force or making it official.
Once a policy has been adopted, it might be enforced. This is to take action under a policy to ensure that it is not violated.
To make policy could apply to formulating/developing it, or to adopting it. To write a policy is to set out policy in concrete written form, which may involve developing it as well. To revise a policy is, as one might expect, to change it in some way.
To violate a policy is to act contrary to it.
There are certainly other verbs that could be used, but these are the ones I think would be most often used in relation to policy.