The Key Technology Research On Expressway Interchange

Interchange ramp capacity, the minimum spacing of interchanges, distribution lane setconditions of Interchange, safety evaluation ofinterchange are researched by mathematicalanalysis, probability theory analysis, computer simulation in this paper, and the correspondingresults are obtained as follows:Based on in-depth analysis of the operating characteristics of the interchange ramp intraffic, different type ramp adaptation capacity model are built by mathematical modelingmethod, and capacity to adapt to different types of ramp design speed are proposed, and thenthe theoretical support for the amendments and additions to ramp capacity in "specification"and the reasonable control of the interchange scale.As the research object to the addition of auxiliary lanes adjacent interchange, selectingthe collision rate f as weaving area traffic safety evaluation, the security levels of interweaveare classified by cluster analysis, then the classification of safetylevel are quantified by thefuzzy evaluation method, weaving area of class A and class B are simulationed by theVISSIM technology, the main efficiency indicators relational model that impact intertwineddistrict traffic operations safety are biuilt between collision rate and the length of the auxiliarylane l, lane minimum spacing of additional auxiliary of adjacent interchanges are established.According to the detailed analysis of the factors that affect the distribution lanes setconditions and vehicle the weaving area running characteristics, the interchange vehiclesintertwined run model are established by the use of mathematical modeling. And bycalculation methods of the weaving area service level, under the conditions of meeting acertain level of servicelevel, the maximum turning traffic adapting to weaving section lengthare calculated. And then according to the results obtained, using VISSSIM traffic simulationsoftware simulatesto test the correctness of the results.In the end, the set conditions ofdistribution lane are establishedto provide a theoretical basis for the revision ofthe"specification ".Based on the detailed analysis of the factors of interchange security, combined the"specification" and "Guidings", the spacing and the form of the interchanges, ramp and itsentrance, auxiliary lanes, variable speed lane length, security-horizon of interchange rangeand transport facilities along the laid are researched. The valuation methods and standards ofcollector-distributor road, auxiliary lanes, variable speed lane, ramp-horizon, diversion pointline-of-sigh, confluence line-of-sight and the safety design measures of the pass triangle areaare established. Then the interchange ramp linear design is controled by the principle of speed difference between running speed and design speed.