Trac 0.8 and later (not yet released) supports ​mod_python, which speeds up Trac's response times considerably and permits use of many Apache features not possible with tracd/mod_proxy.

Here's a typical Trac CGI/Apache setup:

ScriptAlias /trac/myproject /path/to/python/share/trac/cgi-bin/trac.cgi
<Location /trac/myproject>
   SetEnv TRAC_ENV /var/svn/trac/myproject
</Location>

The equivalent mod_python setup is:

<Location /trac/myproject>
   SetHandler mod_python
   PythonHandler trac.ModPythonHandler
   PythonOption TracEnv /var/svn/trac/myproject
</Location>

Note: you might need to create a real physical trac directory (to match the first location path segment from the above example) inside your DocumentRoot so that Trac can figure out the correct base location. That seems to be a problem (or feature?) with mod_python.