In Offenbach, immigrants predominantly are located in or close to the city centre in densely populated districts (defined as equal or above median of 6506 inhabitants per km2). Two-thirds of the immigrant participants, but only 38% of the non-immigrant participants, live in these inner-city districts.
About two-thirds of the immigrants are born outside of the country (first immigrant generation N = 576, second immigrant generation N = 263). Their years of arrival vary between 1959 and 2010. About half of the first immigrant generation arrived before 1987. On average, they have lived in Germany for 24 years at the time of the survey and were 19 years old when they immigrated to Germany. 22% came to Germany as children (age 10 or younger) and 34% as teenagers and young adults (age 10–20).
As shown in Table 1, socio-demographic factors differ between the two groups. As expected, immigrants are younger than non-immigrants, they live in bigger households and they are more likely to live with children under the age of 18. Immigrants have a lower average household income. This is also true for the average equivalent scale income that takes into account that the financial needs of a household increase with each additional member but not proportionately. Immigrants are more likely to state that they are still in school or at university or completing an apprenticeship. They are also more likely to be unemployed than non-immigrants, but less likely to be already retired.
Descriptive results—preconditions and transport mode use
The two main prerequisites for people to drive a car are a valid driving licence and car availability. As shown in Table 2, the vast majority of non-immigrants were found to live in households with at least one private car, and this is also true, albeit to a lesser extent, for immigrants. A similar pattern can be observed when it comes to parents’ households with a car, but here, there is a significant difference between the two groups. With regards to the average number of cars per household, there is a small, but statistically significant difference. A smaller share of immigrants has a driving licence. The vast majority of all drivers state that a private car is always or sometimes available. In contrast to driving licences, men and women have access to a car in an almost equal manner.
All participants were asked how often they tend to drive in the car as passengers and those who had access a car were asked how often they tend to drive the car themselves. As shown in Table 3, the majority of drivers use the car either every day or several times a week. Male immigrants are the most frequent drivers, whereas immigrant women are the least frequent ones. When it comes to the use of cars as a passenger, the picture changes: Women were found to be passengers more often than men, and non-immigrants less often than immigrants (Table 4).
Offenbach is known to have a rather good public transport system and 87% of the participants indicated that they walk less than five minutes to the nearest bus stop. As shown in Table 5, irrespective to gender or immigrant status, more than half of the participants stated that they use public transport only on a monthly basis or less. For both groups, the major reasons for not using public transport are that there is a car available and that it is more convenient than public transport.
The preconditions for riding a bicycle are similar to that for driving a car, as a person needs to have the ability and the opportunity to ride a bicycle. As shown in Table 6, bicycle ownership per household is quite high in both groups, but there is a significant difference: Immigrants more often live in households without any bicycles, and they own, on average, not as many bicycles than non-immigrants. The majority of participants in both groups know how to ride a bicycle, but immigrants, especially women, are less likely to have this ability. The two groups also differ in terms of their access to bicycles. But in each group, there is no difference between men and women.
Participants who knew how to ride a bicycle and had access to a bicycle were asked how often they tend to use it. As it is shown in Table 7, bicycles are used more frequently by non-immigrants than by immigrants, especially by men. Even though there are slightly more immigrant women than men who use the bicycle almost every day, the former have the highest share of non-cyclists. For both groups, reasons for not using a bicycle include that they do not enjoy riding a bicycle or it would take too long, that there are health reasons or that it is inconvenient to use it with (small) children or to transport groceries. The lack of safe bicycle paths and of parking facilities was primarily mentioned by non-immigrants. In contrast, immigrants were more likely to state that they do not have access to a (functional) bicycle.
Results of logistic regression models—influencing factors on the regular use of car, public transport and bicycle
The results mentioned above point to some important differences in transport behaviour between non-immigrants and immigrants. To arrive at a more nuanced understanding of factors that influence mode use, we developed logistic regression models. We used iterative procedure for parameter estimations. Additional variables such as household income, or immigration background were successively added to the socio-demographic base model to test different model variations and to identify important influencing factors and the biggest effect sizes. Most independent variables were put into the models as dummy variables. Number of bicycles per household, the distance factor, the socialisation factors and a statement addressing participants’ sense of security in their respective neighbourhoods were put in as numeric variables. Tables 8, 10 and 11 show the results for the car model 1 and the public transport and bicycle models. They include the immigration background. Car model 2 (Table 9) includes for the first immigrant generation different categories for the duration of stay and the second immigrant generation as dummy variable. All tables provide the estimates for regression coefficient B (reg. coeff. β), odds ratio (OR) and average marginal effects (AME).
Tables 8 and 9 list the results for estimating the parameters of car use (driver). Both models include the same parameters with the exception of immigrant status. In both models the largest positive effect can be observed for household income. The highest income category has the biggest effect, meaning that the probability of car use increases by about 30% if an individual lives in a household with more than €1801 per month at its disposal (AME in comparison to the reference group). The household composition, its location and socio-demographic factors affect car use as well. Three factors-living alone, living in a densely populated area and being female-all considerably decrease the probability of car use. Age is also a significant factor: In comparison to the young reference group (18–3 years), the probability of car use is higher for the two other categories. The socialisation factor car-attitude combines four statements with positive attitudes towards car driving and gaining a car licence as a young adult; here, an increase implies stronger positive attitude. The stronger the attitude, the more likely it is that participants use a car. Immigration background lowers the probability of car use but the effect is very small and not significant (Table 8). In Table 9, the immigrant generations are looked upon separately and duration of stay is taken into account for the first immigrant generation. More recent immigrated participants with a shorter duration of stay were less likely to drive a car on a regular basis. In comparison to those participants who were born in Germany, the two categories with shorter duration of stay both show a negative effect. The effect is significant only for the first category that includes immigrants who lived in Germany for up to 15 years. For those who lived in Germany for at least 30 years, the effect is positive, but very small. Belonging to the second immigrant generation increases the probability of car use.
Table 10 lists the results for estimating the parameters of public transport use. The variable dealing with education (attending school, going to university or doing an apprenticeship) has the largest positive influence: The probability of public transport use increases by about 34 percentage points. Positive effects can also be observed when it comes to gender and immigration background, but both have only a small effect. All the other variables show a negative effect on the probability of regular public transport use. Living in a household that owns at least one car considerably reduces the probability of using public transport. To a much lesser extent, this is also true for individuals living in households with children. Another negative factor is age. In comparison to the young reference group, belonging to one of the two older age groups has a negative effect on the probability of using public transport on a regular basis. An increase in car-attitude reduces the probability of using public transport on a regular basis, as suggested by a small but statistically significant effect.
Table 11 lists the results for estimating the parameters of bicycle use. The largest positive influence is the factor of living in a household that owns at least one bicycle, which considerably increases the probability of riding a bicycle on a regular basis. Similar to car use, age is a positive factor: In comparison to the young reference group, the probability for the use of bicycle is higher for the two other categories. A positive influence can also be observed for an increase in the bicycle-socialisation factor, which combines the statements on parents’ bicycle use with the one that asked whether participants’ were accompanied by their parents when riding a bicycle as a child. A similar effect has the neighbourhood statement about feeling secure even when it gets dark, but to a smaller extent. A decrease in probability can be observed for those participants who live together with children. Being a woman, having an immigration background or travelling further to locations for work, education or grocery shopping affects the likelihood of regular bicycle use in a negative way, but only to a smaller extent.