Dalia and Maya didn't know they were trampling on religious sensibilities when they boarded a No. 418 Egged bus from Beit Shemesh to Jerusalem on a Thursday afternoon. "Please get up and move to the back of the bus," two bearded men in suits and hats told them a few minutes into the journey. "This area is reserved for men. Women sit in the back." Maya was astounded. "This is public transportation, I thought," Maya told The Jerusalem Post. "I have a right to sit wherever I want to sit." "At first we ignored them," she said. "But additional men boarded who were more insistent. The driver said that he did not want to get involved and Dalia got up and walked to the back. I did not want to fight all those men alone, so I went to the back too. I felt threatened." Increasing haredi buying power is forcing Egged to change its services. Egged, the nation's largest bus company with 1 million passengers a day, operates 24 inter-city "mehadrin" lines on which men and women are segregated. Egged refers to them using the euphemism "designated (ye'udim)" lines. Mehadrin is a term used for strict observance of Jewish legal strictures. In the context of public transportation, mehadrin means that the laws of sexual modesty are observed more stringently. Men and women do not come into physical contact and they try not to even see one another. Women enter the bus from the rear door and sit in the back. Normally the driver comes to the back of the bus to collect fares or to punch a ticket. Men sit in the front. Egged drivers do not oversee the gender separation. Nor are mehadrin buses marked as such. (An Egged spokesman said that because a bus was often used for both mehadrin and regular lines it was logistically impossible to mark them.) Rather, regular passengers know which buses are mehadrin and sit accordingly. Passengers like Maya and Dalia who do not know are notified by veteran passengers, who see themselves as responsible for enforcing the segregation. The separation is part of a larger haredi trend of encouraging more modest behavior in the public sphere. Other examples include a recent rally attended by leading Lithuanian yeshiva heads protesting "immodest" female fashion trends in the haredi world and the initiation of El Al flights that provide "kosher" movies produced and directed by Moshe Levi, a Gerrer Hassid, and same-sex seating. Haredi spiritual leaders believe the immodest influences of secular society cause calamities in the haredi world, including sickness, poverty and godlessness. Egged has been operating mehadrin lines for five years, the first of which was the No. 402 between Bnei Brak and Jerusalem. Eleven lines have been added in the last six months. The latest began operating less than a week ago between Arad and Jerusalem. According to sources at Gal BSD, an advertising agency that specializes in the haredi market, Egged added the lines in response to a consumer survey that found the vast majority of haredi bus passengers, both men and women, preferred separation of the sexes. The rise in the number of lines is also an indirect result of the haredi exodus from urban centers over the past decade, said Aryeh Frenkel, a PR executive at Gal BSD who works with Egged. Skyrocketing real estate prices and falling quality of living in traditional haredi centers such as Bnei Brak and Jerusalem have gradually pushed entire communities to outlying areas such as Beit Shemesh, El Ad, Kiryat Gat, Hatzor Haglilit, Arad and Netivot. Existing haredi neighborhoods in Ashdod and Haifa have grown. Often these new neighborhoods are created in an organized way. Groups of relatively homogenous haredi communities band together and commission the services of contractors who agree to build an entire neighborhood, complete with synagogues, parks, mikvaot (ritual baths) and educational institutions. The contractor is assured that he will not be burdened with unsold apartments while the haredi community gets more for its money. Residents of these neighborhoods rely almost entirely on public transportation. A leading haredi ad agency estimated that fewer than 20 percent of haredi families own a car. Occasionally non-haredi people like Maya and Dalia, who are specialist teachers in the Ramat Beit Shemesh area, unwittingly board the buses. Ironically, Egged had a hard time launching its mehadrin No. 418 line in Beit Shemesh. Four years ago, radical anti-Israel haredi elements such as the Toldot Aharon Hassidic sect opposed allowing Egged to corner the mehadrin market. "When we first asked Egged to run a mehadrin line 14 years ago they refused, claiming it was not economically feasible," said Shmuel Popenheim, a spokesman for the rabidly anti-Zionist Edah Haredit and a resident of Beit Shemesh. "So we established our own transportation. A few years ago, Egged suddenly saw the light. Where were they when we needed them?" Shlomo Hirsch, a businessman and leader in Beit Shemesh's Toldot Aharon community, established the Darka Acharina (The Other Way) transportation company. The name is an allusion to a Talmudic teaching that praises a man who takes "the other way" to avoid seeing a woman and denounces as a criminal one who does not. Community leaders foiled Egged's initial attempts to turn the No. 418 into a mehadrin line by convincing Beit Shemesh residents to boycott the line. However, Egged eventually gained the support of Rabbi Natan Kupshitz, one of Beit Shemesh's leading rabbis, after running a mehadrin line from Beit Shemesh to Bnei Brak that was not in competition with Darka Acharina. With Kupshitz's agreement, Egged reinstated segregation on the 418. However, supporters of Hirsch's Darka Acharina line continue to fight Egged's 418. Three weeks ago, they stoned the 418 after Egged changed the route to include stops in the haredi Yafe Nof neighborhood.