Question: What is the ruling on joining prayers when traveling according to the Maliki teachings?
Answer: According to the Maliki madhab, it is a permissible dispensation (rukhsa) to join prayers while traveling. The travel does not have to be one where the distance allows you to shorten the prayer, you merely have to be out of your city limits. Once you are out of your city limits, and traveling to do something that is not disobedience, then you can either bring Asr (or Isha) forward or delay Dhuhr (or Maghrib) depending on your situation. If you are in a resting place when Dhuhr enters, and you intend to be traveling until Maghrib, then you can bring Asr forward. In the case of Maghrib, if you are resting while it enters and you will then travel past fajr time, then you can bring Isha forward.
To delay Dhuhr or Maghrib, the following is the scenario; If you are traveling while dhuhr enters and you will continue traveling but will stop before maghrib, then you can delay dhuhr. If you are traveling while Maghrib enters and you will stop before Fajr, then you can delay Isha.
So, as an example, you are leaving Liverpool around noon to attend a program after Asr in London. You are on the road when dhuhr comes in but you wont get into London to the masjid until after Asr has entered. In this situation, you can delay dhuhr and pray it with Asr in London. On the way home, you leave before Maghrib enters and then the sun sets while you are on the road. You will get back to Liverpool before fajr and so you can pray Maghrib with Isha when you return.
For bringing them forward; you are travelling from Liverpool to London in the winter time. You stop for fuel when dhuhr is in and you wont get to London until maghrib. You can pray asr with dhuhr.
To illustrate using this dispensation in times other than when you shorten prayer: You live in Liverpool but you need to go to Warrington. You leave before Maghrib and the sunsets after you have left your city limits. You will be out and about the whole time in Warrington until you return but then maghrib will be out. You can delay maghrib and pray it with isha.