In Michigan, a defendant needs permission of the court and/or probation to travel outside of the State of Michigan or to leave the country during probation and during bond.
As a former New York City and Michigan prosecutor, I was on the other side of many travel requests from defendants. While I generally left the decision up to the judge, I was often asked by the judge what my position on the matter was - this puts a young prosecutor in a tough position, because a prosecutor brings the charge against the defendant, but isn't necessarily in a good position to determine if someone should be able to travel during a criminal case.
The problem is most young prosecutors are blinded by their role and believe they must argue against whatever the other attorney is requesting. This is a very silly and unnecessary thing to do, but most prosecutors don't have a ton of common sense. As a former prosecutor I would generally tell the judge "we leave that to the discretion of the court" rather than agreeing or disagreeing. If the prosecutor responses with a "NO, they shouldn't travel" then the judge is in a spot where he needs to decide for one side, rather than agreeing to something both parties are in agreement. Some prosecutors just don't know how to agree to something even if its the reasonable thing to do.
As someone who works with clients now, I take this experience and make sure that I speak to the prosecutor before making my request to the judge. I anticipate the judge probing the prosecutor for a response, and instead of relying on that prosecutor reacting in a reasonable way when surprised on the spot, I give them a heads up and run it by them. As long as my client is not currently in violation of bond conditions or giving a reason to be concerned, the prosecutor will usually agree "sure, that's fine with me, I don't oppose". That way if the judge does ask, the prosecutor is already thinking about it, and doesn't need to respond with a rash and quick answer that might jam my client up.
Based on my experience as a prosecutor, I have also developed a proactive approach to all cases, which I discuss in great detail in other writings, books and articles. This approach is essential in assisting my clients gain permission to travel out of the state or country during a pending criminal case. If my client is charged with a drug or alcohol offense, we have already been testing more than most are required, and if its alcohol, we are likely on a portable unit, which gives the judge every reason to allow travel. My clients are typically already in counseling, education programs and on the right path during the case; they have earned a bit of the benefit of the doubt and risk losing that benefit if they run into issue while traveling.
Lesson is don't assume a judge and prosecutor will apply common sense or give you the benefit of the doubt. Even if the travel is for work, a family wedding, something "required", that doesn't mean you will be allowed to go.
Plan in advance, talk about it with your lawyer and make sure you're doing something than just asking in order to get permission. Show the judge and prosecutor you deserve that permission, don't assume you'll receive it.