In this paper some preliminary results are presented for a fast non-steady state creep force model which is based on Kalker's simplitied theory of rolling contact (J. J. Kalker, Vehicie Syst. Dynamics, 11 (1982)1-13). Problems with moderate non-steady state creepage and small non-steady spin can be treated at a very high speed on a personal computer with this method. Comparison made with CONTACT (J. J. Kalker, Three-Dimensional Elastic Bodied in Rolling Contact, Kluwer, Dordrecht 1990). shows its promise for dynamic simulation. further effort to reduce its error and to make it suitable fortreating non-steady normal force and non-steady varying contact patch is needed.

The seriousness of the rail sidewear problem on Chinese Railways has been describedin this papar. Things account for the occurance of this probiem and measures takon to solve it are discussod. Recommendation on improvements of the rail quality an rail maintenance are given as conclusions of this paper.

介绍了轮轨高速铁路技术的最新发展及磁浮高速列车国内外的试验研究情况。按不同速度等级将两种铁路高速技术加以对比，指出只有在需要将地面交通的速度提高到400km/h以上时，磁浮高速列车才具有优势。着重论述了京沪高速铁路采用轮轨技术的必要性和可能性。呼吁尽早统一认识，以便能如期在“十五”期间开工修建京沪高速铁路。

研究了现有文献关于高速列车动力学方面的论述，就高速磁浮列车对轨道的动力作用及其与轮轨高速铁路的比较展开讨论。得到的主要结论是：地面高速轨道交通应以300km/h左右的轮轨高速铁路为主体；在需要400～00km/h超高速的特定条件下，也可以采用磁浮高速列车，作为一种补充。因此，一方面要积极修建上海浦东机场高速磁浮试验线，一方面要尽早启动京沪轮轨高速铁路的建设。