If it was me I would do a quick test to see if any taps are needed. First disconnect the last track section before the power base. Put a car on that section with its rear wheels off the track and punch the controller for that lane. Measure the voltage on the power section and on the last section. Repeat that for each lane, if the voltage drop is more than a half volt you would first need to locate and fix any poor connections. If the voltage drop is still too high add some jumpers, just one set of jumpers half way around the track might be all you need. Adding a lot of jumpers when your track joints are not good is only a partial solution to the voltage drop problem. If you run cars with powerful traction magnets or with powerful motors that will also tend to increase the voltage drop. Any sectional track can develop faulty joints with time, especially if you run cars with big traction magnets because that flexes the track.
If you do need to add jumpers Scalextric used to sell those. I have made jumpers from phosphor bronze sheet that I got at a hardware store.


These are a press fit and do not have to be soldered to the rails.