Switching Model for Private Vehicles to Public Transportation System in Case of Sana ’ a 1

The latest statistical information of rapid increase in the use of the personal transport generally in Yemen and especially in Sana’a illustrate that 80% of the registered vehicles in the country are own cars and taxis which numbers have increased tremendously recently which is the cause of the increasing of the traffic congestion, accidents, inadequate parking space and air pollution, among other problems. Earlier studies in this subject, however, focused primarily on car safety issues rather than identifying factors influencing car use and car user mode choice behavior. Due to these problems, the objective of this study is focused on shifting car users to public transport mode transport and discussed the factors to encourage the traveler to shift towards public transport in order to increase road safety and enhance road environment. The data collected and demographic details are analysed like age, gender, educational level and travel behavior in regard to the transportation mode. For a description of the survey data, SPSS is used and logit model is applied. The questionnaire distributed in Yemen which is designed based on social or economic preference, trip characteristics and probability of shifting from private vehicles to public transportation mode. The obtained results reveal that the time and cost and convenient has a momentous role in encouraging the private vehicle users to switch to public transport.


INTRODUCTION
Urban population growth determines the progress of transport sector in the concerned region (Region, 2006). The bigger the city or its growth, thus is the growth of transport infrastructure. Moreover, the income growth makes people prone travel much more (Ismail et al., 2012;Shokri et al., 2009a). Both in developed and developing countries, congestion is a major problem in many urban regions (Altef et al., 2013;Shokri et al., 2010). Traffic congestion occurs when the supply does not meet the demand. It is a barrier for the free movement and business in the urban regions. Urban cities in developing countries have several factors that creates problem to sustainable transport system. The population, high income, rapid growth of cities and urbanization has led increase in travel demand. Service of transport sector has not been up to the mark in developing countries and most transport facilities fail due to lack of proper planning and design. Besides, pedestrians and non-motorized vehicle users are less considered when planning urban transport system that creates mixture in the roads and further complications. Most of the people afford to have private vehicles and hence the vehicle population has also boomed. Extremely congested roads with all types of vehicles and passengers, traveling different speed are the situation of Sana'a roads. This is further worsened by lack of public transport facilities and space. Air pollution and other environmental hazards are also yet another concern (Almselati et al., 2011).
The case study of the current study is Yemen which is bounded by Sudia Arabia from the north, east by Oman, south by the Gulf of Aden and west by the   Figure 1 shows the location of Sana'a is one of the oldest continuously inhabited cities in the world. At an altitude of 2,300 meters (7,500 ft), it is also one of the highest capital cities in the world. the number of populations Sana'a are 1747627 in 2009 and area of Sana'a 1604 km ଶ making it Yemen's largest city (TMOCCS, 2010). Yemen is a developing country which suffers the consequences of explosions in both human and motorization. This has been accompanied by a heavy toll of deaths and economic cost. There is currently no public transportation (buses) and no rail or metro network but one will also be built. The public transport system in Yemen is very poor and hence, the private transport increase was observed in private transport. Generally, non-motorized transport means to walk or use bicycles (Ryley, 2006).
In Yemen, the car, due to its inexpensive cost, has been a popular mode of transport in it. Consequently, casualties among car users constitute a high portion of total fatalities in these countries. The people are less non-motorized transport users, motorcycles increased in Yemen, it use large of motorcycles in the cities. Motorcycle is popular in Yemen and use it as a taxi especially at peak time of congestions, the number of motorcycle registers at 2008 are 10769 and the numbers of motorcycles not register more than this number (Central Statistical Organisation (CSO), 2011). Motorcycle users are more vulnerable to fatalities and injuries (Beck et al., 2007). The motorcycles are allowed in highways; safety measures like compulsory wearing of helmet and exclusive motorcycle lane are not prevalent in Yemen. More than half of total traffic fatalities are death related to motorcycle accidents (Kulanthayan et al., 2000). The increasing numbers of motor vehicles in Yemen, all kinds from own cars, private transport, taxis, motorcycles , trucks and heavy equipments as indication of the severity of congestion on major roads between main and interior cities (Almselati et al., 2011). Table 1 Taxi and bus  Truck  Total  2001  3462  1350  1997  6809  2002  2039  532  453  3024  2003  1958  448  257  2663  2004  7866  2031  514  10411  2005  14002  3588  774  18364  2006  8641  1872  2886  13399  2007  9336  2305  9180  20821  2008  13811  2878  3752  20441  2009  14150  1550  4563  20263  2010  16454  380  3401  20239  Total  91719  16934  27777 136434  Yemen. Table 2 illustrates the registered vehicles in Sana'a in 2001 to 2010. Yemen has started using higher quality cars and companies are starting to take over the taxi business (TMOCCS, 2009). Transport system provides many benefits, but it also causes many problems. It serves non-drivers poorly, distributes benefits and costs inequitably; financially burdensome to households, governments and businesses, increasingly inefficient due to traffic congestion and dispersed land use, a major cause of death and disability, contradicts environmental and quality of life objectives and relies on non-renewable resources that may become scarce in the future (Litman, 2003;Shokri et al., 2012a).
Yemen is one of the most affected countries of the traffic accidents, the number of fatalities due to accidents of cars between deaths and injuries in 2009 are 22034 (WHO, 2009), the social and economic impacts of traffic accidents are very large annual losses of money in addition to the losses and the high proportion of social orphans and the disabled. Table 3 presented the number of accident, fatalities, serious and minor injuries and cost for main cities in Yemen such as Sana'a, Aden, Taiz, Hadramoot and Alhodeidah on 2010. Table 4 presented the cost of Road Traffic Accident from 2001 to 2010 in Sana'a city. Road traffic risk may be defined as the probability of accident, injury, death and damages for a given amount of activity or exposure. Accident There is reason to believe that the risk increase for young car drivers is connected to the increased risk at night or weekend days. Accidents by young drivers are typically single accidents especially at night during weekends (Ismail and Elmloshi, 2011). Road accidents were the main reasons cause of all deaths in Yemen as example Sana'a city the death, injuries and road accident as below in Table 4 (TMOCCS, 2010).
Base on the mentioned literature, the rapid increasing car users in Yemen and especially in Sana'a has resulted in congestion, accidents and casualties has prompted to undertake various studies to address this problem one of these studies was the shift of transportation mode from private car to public transportation in Yemen.
This study made an attempt to determine whether car users switch to public transportation mode if the Public Transportation (PT) is improved by decrease the travel time cost of PT and analysis the elements which are interfere to the travellers' decision for mode choice such as travel time, cost, convenient, safety and traveller habits.

MATERIALS AND METHODS
In this section the methodological analysis parts which are consists of data collection method, opinion that is used in this research for collecting data, model development and evaluation as well as the analytical and conceptual structure of the research are expressed as well.
In many capital cities of Arab countries including Sana'a the increasing number of car users involved in crashes and the associated injury travel demand management has been receive increasing attention for its potential to improve urban transport problems with undertaking various solutions to solve this problems. While managing urban travel demand is not only planning the transport system but also to get solution the issues of traffic congestion, accidents and environmental pollution from the increasing use of vehicles (Elmloshi and Asmail, 2010), shift model from private vehicle to public transport mode is another solution for this problem.
Model choice activities and the switch from private to a multimodal public transportation mode are investigated through data collection and interpreted using SPSS and logit choice model. The selection of data gathering methods according to Sekaran (2003) depends on the available facilities, the degree of accuracy required, expertise of the researcher, time span of the study, resources available for data collection and other related costs. It's expected to guarantee an excellent questionnaire design and the appearance of obvious and shared approach to the definition of related parameters. The questionnaire is expanding to directly address the objectives of the research.
There are two methods were followed to obtained information about numbers and type of cars, road traffic accidents and their injuries. In the first method is from Traffic Management Office for Capital City Sana'a TMOCCS, road traffic accidents database was published since latest 1991. All information about road traffic accidents and numbers and types of vehicles in Yemen was obtained from TMOCCS and Central Statistical Organization in Yemen CSO. The second method surveying was carried in selected roads in Sana'a city area where there were higher car ownership users and micro buses and taxi available. The survey was done by questionnaires to get relevant data.
Two basic approaches are used in this study for data collection, Revealed Preference (RP) which is focused more on personal information and Stated Preference (SP) methods that concentrate on trip characteristics. The respondents for this survey are the own car, taxi and mini bus users in study area who use their mode to go to work, study and shopping. The respondents selected randomly. The data collection was done through field study observation and survey. The survey was done using questionnaires to get relevant data. The respondents for this survey are the own car users at study areas who use own car to make their trips to work, study and shopping and the citizens who did not use own car in their trips. Brief questionnaires will be formed to ensure for user's comprehension and they are in the form of open and close ended questions. The questionnaires were printed by two languages, Arabic and English language, to provide easier understanding and answering for some respondents. There are three sections in this survey. Section A is about respondent's personal information that will help to get the respondent's basic information for this research. Section B is a section that requires respondents to fill in information about their trip characteristics and purpose such as work, study and shopping trips. Section C only for use own car their portion are 73.6% ,which wrote notice for that in questionnaires and any respondent not use own car their portion 26.40% not fill this section because to know how many use own car in respondents and to recognized the their feeling when to ask them about shifting to other modes. There are several questions that correspond with respondents' views, recommendation and opinions. These questions provide the opportunity for the respondents to give their opinion. The questions are formulated in such as way that could help the respondent answer the questionnaire easily and quickly. Respondents will be selected randomly from residential areas which does not have public transportation services. The selected respondents are based on private transportation vehicle (taxi and mini bus) and own car users who use their private vehicles as their mode of transportation to go to their trips. The questionnaires were pre-tested by a pilot survey. The purpose of the pilot survey is to test whether the respondents understand the questions. Also pilot survey is purposely done to see the pattern of answers given by the respondents. Fifty applications of questionnaires were distributed in Sana'a city. These fifty respondents were selected randomly from own car and private transport vehicle users in Sana'a city. A total of 1000 questionnaires were collected in 8 months from (Sep. 2010 to April 2011). Statistical Package for Social Science (SPSS) version 17.0 and Microsoft office Excel 2007 software were used to analysis the questionnaire.

Alternative mode of transport for car users:
According to the increasing the number of the private vehicle number (Hill, 1965), the study made an attempt to determine whether car users had access to other modes of transport or not (Fig. 4). Based on the analysis of the collected data, about 51 % of car users had access to the public transport mode, while 21.80 % had no access to alternative modes and 26.4% already not used car own car. Therefore the total number of car users had access to other modes are 78.20%.
Based on Fig. 5 the collected data illustrates that the 26.4% of the users don't use the PT for their travelling, 39.9% of the traveler believe that the PT condition is poor, 28.8% and 3.6% of the travelers are considered that the PT is good and very good mode respectively and 1.3% think that the current PT has an excellent condition and performance.
Analysis of the collected data reveals (Fig. 6) that the improving the condition of the PT has the straight impact on the mode choice of the travelers. While the own car users prefer switch to public transport by 31.80% would shift to bus as an alternative mode of transport, 15.50% would access to Light Rail as an alternative mode of transport, 9.90% would access to Under Ground as an alternative mode of transport and 13% would access to public taxi as an alternative mode of transport, 2.10% would access to other such as motorcycle or bicycles and 26.40% already not use own cars.
Reasons convince to switch from using own car to public transport: In considering the reasons convince to a mode shift from car travel to public transport, it is necessary to understand the factors, which support the great majority of active car users to using Public Transport (PT) system as a regular means of transport. Table 5 presented the major reasons identified when survey respondents were asked to name or, select from a given list, the factors which would influence their decision to use Public transport. The factor of most significance encouraging car users to using the public transport was that the "High traffic congestion and delay". This statement received an average rating of:    unproductive times on the road. Reduction of travel time by introducing public transport mode will encourage users or drivers to switch to this mode. The switching to public transport mode may reduce traffic congestion, improve travel time and increase road safety. The results from the study shows the users or drivers or travelers prefer to switch to public transport if the travel time for trips road network improved significantly. Improvement or reduction in travel time by 10% will encourage about 5.8% to switch, reduction of 30% will encourage about 11.30% to switch, reduction of 50% will encourage 38.50% to switch, reduction of 70% encourage 14.30% to switch and finally reduction of 90% encourage 3.70% to switch to the public transport (Fig. 7).

Improving the travel coast for the public transport:
The other factor affect decision making in choosing travel mode is travel cost. Travel cost is considered an important reason for mode choice. The results from the study shows the users or drivers or travelers prefer to switch to public transport if the travel cost for trips road network improved significantly. Improvement or reduction in travel cost by 10% will encourage about 6.9% to switch, reduction of 30% will encourage about 11.30% to switch, reduction of 50% will encourage 35.80% to switch, reduction of 70% encourage 15.60% to switch and finally reduction of 90% encourage 4.0 % to switch to the public transport (Fig. 8).

CONCLUSION
This study indicate the needs of introducing an efficient public transport system to reduce the traffic problems such as traffic congestion, road accidents and delay in travel time on roads network for all trips. The study attempted to conduct mode choice behavior of travelers and trip characteristics of two modes of transport namely car and public transport. Utility of the two modes were compared to determine the important reasons behind the choice of a particular mode and the circumstances, which might cause travelers to change their choice for the car. In order to promote greater use of public transport, this study examined the effect on car use if total public transportation travel time, travel costs the results suggest that travel time and travel cost are characteristics that determine why car use is a favored modal choice. The findings of this research can be concluded that the travel time and travel cost have significant influence on model shift from car to public transport.