On a long layout when a train slows down the further it gets from its power source is a common issue. My question is how do you wire power to the track to boost the trains current. Attaching to the track is not a problem but how do you connect back to your transformer.
Your train's speed is dependent on the voltage the locomotive receives. This voltage is controlled by the speed setting on your power pack or transformer. A voltage drop can occur over a long length of track especially if your rail joiners are not tight and if the track feeds are not soldered to the rails. Other things which can contribute to voltage drops are, dirty track, dirty wheels or dirty sliding track contacts.
To deal with these problems, you can power the track from multiple places. While you can use a terminal strip connected to the power pack and branch off from it to any number of track locations, it is better to run bus wires from the power pack and to tap off these wires to feed the track at regular intervals rather than just at one point. You can experiment to determine how many feeders are needed on your layout.
Just be sure to use different color bus wires for the positive and negative terminals on your power source and make sure that proper track polarity is maintained at every connection. Also, buss wires are of a thicker gauge than track feeders.