NFPA 79 Section 13.5.2 states that "the combined CSA of all conductors and cables shall not exceed 50% of the CSA of the raceway.

My question is can this value be greater than 50% if the temperature of the cables in the raceway does not exceed a temperature of 60 degrees C for example during normal running?

No. Cross reference NEC 376.22 Max is 20%.

The way your question is stated implies that you are not up to speed with all of the subtle intricacies of applying the Code. The rating of 60C means that the wire will collapse its properties (insulation, resistance, etc.) at rated current. If indeed you were operating anywhere near that, say 41C, then you need to use a multiplier, derating your calculated Amps to size the Wire. Example: your Load is 51A, the surrounding air might reach 106F (very particle), while you might consider using 6AWG (60C) Wire, you need to apply NEC Table 310.15(B)(2)(a), or NFPA-79

{12.5.5(a) }--> (0.71).Therefore, 51A / (0.71) = 71.8A, back to Table 310.15(B)(16), or NFPA-79

{12.5.1}= 3AWG.If your application approaches 56C, consider using 90C Wire where the multiplier for 56C = (0.71), and take note that a multiplier doesn't even exist for 60C Wire with surrounding temperature possibly reaching 56C - you can't use it! This multiplier is seldom used, it's critical in preventing fires, and should be utilized at 'worst case scenario' surrounding temperatures.