Train Route Umschlagplatz to Treblinka

Topographical analysis of possible train routes leading from the Warsaw Ghetto Umschlagplatz, across the Vistula, to Wołomin, 1942-1943.
Note - In the referenced interview, Nechama Epstein-Kozlowski indicates she jumped from a train she believed was heading to Treblinka. She indicates she had jumped somewhere near Radzin, Lukow, and Miedzyrzec. This could possibly mean that she was on a transport of Warsaw Ghetto inhabitants to another ghetto, to another killing center, or proceeding to Treblinka via Lukow and/or Siedlce.
Note:
In his book, 'The Holocaust Kingdom', Alexander Donat writes the following about being deported from the Warsaw Ghetto:
"We made up our minds that if the train went toward Treblinka, we'd jump off; death by a bullet seemed preferable to the gas chamber...The red glow of the burning Ghetto followed us as our train crossed a bridge over the Vistula and circled Warsaw, moving slowly, laboriously, switching from track to track on its way to the East station. The glow grew distant and darker. We clattered over a viaduct and then the train was unmistakably headed south, toward Lublin."
This may indicate that the train crossed the Vistula at the Gdański Bridge and 'circled Warsaw' as it made its way south toward the Warszawa Wschodnia station (East station). From there it would have traveled toward Rembertów if headed toward Treblinka but instead of heading north on the branch line, the train headed south toward Lublin.