  With the continuous improvement of urbanization and motorization, travel
demand in historical blocks is higher than before. The contradiction between
supply of transportation facilities and environmental protection is more
serious. Traditional public transport planning methods aim to improve mobility.
However, several existing studies do not put travelers in the first place,
which ignore quantitative description of land uses and the characteristics of
travelers. This paper intends to improve individual accessibility of public
transportation in historical districts. Based on POI data, the calculation of
accessibility combines the utility model and spatial interaction model. To
optimize public transportation, the goal of improving individual accessibility
is transformed into reducing residents' travel negative utility. Using a
real-world dataset in Beilin District of Xian, the performance of the proposed
model is evaluated. This paper calculates the present accessibility and uses
ant colony algorithm to optimize public transportation. The results demonstrate
that the calculation and optimization of public transportation accessibility
are practical, which are also valuable to public transportation planning and
organization in historical blocks.
