Firstly, the necessity and the threelayer system of traffic zones are stated, and the concepts of key intersection and gatheringdispersing intersection are put forward.

Some key interfaces in implementing process were introduced.

The earned value analysis in project schedule based on critical path;

Workflow critical path algorithm based on activities;

The activities sequence in critical path of highway project network;

Convenient matrix calculation method for critical path in twin code network chart;

This paper analyzes the time-scaled network plan applied to confirm critical path,gain time factors,control network plan and so on.

Based on the study of calculating approaches of fuzzy network,this paper puts forward a new method to calculate the parameters and determine the critical path of fuzzy network planning.

We know that the operation processing time length in a schedule can be calculated through critical path of the corresponding chart.

Proceed to the technique battlefield the test equipment reforms,increasing well-trained degree of the personnel,by using the concurrent technology and the critical path technolog.

According to the characteristics of interval plan network,this paper introduces the concept of interval critical path(DBICP).

Solve the critical path problem by the shortest path method;

This paper focus on deploying resource,make use of the different completion probability of critical and un-critical path,the authors suggest a schedule optimization algorithm based on transferring resources from un-critical path to critical path purposely,and the result of applying the model shows that the method is practical for optimizing project schedule with resourc.

The limitation of the PERT in the planning of construction schedule is studied for two cases, where there are several critical paths, or the sub critical path is close to the critical path.