Within any community, state or country, roads infrastructure represents a key factor for the economic and social development of its population due to the amount of merchandise and people mobilized through it (Vassallo et al., 2010).

According to the Ministry of Communications and Transportation of Mexico, in this country 96% of passengers and around 55% of freight transport use roads and highways (SCT, 2013). Therefore, a single road could be substantial to the execution of multiple productive activities from the diverse communities interconnected and benefit by it.

Federal Highway No.5 covers a 190 kilometers rout from Mexicali City, capital of the metropolitan area with the same name, to the locality of San Felipe which is found  at   the   south   of   the   county.   The  rest  of  the metropolitan area is constituted by 15 localities, most of them located in the agricultural valley known as Valle de Mexicali (INEGI, 2005b). This valley is a suburban and rural zone, located at the southeastern periphery of the metropolitan area; it has a high level of marginalization due to the lack of infrastructure and services such as water supply or sewage collection and disposal systems (CONAPO, 2012). For this research were considered the ten localities with the bigger number of inhabitants, a better access from the highway axis and the larger territorial dimensions.

The road infrastructure contributes to the development of educational, cultural and health services (Romero, 2001), which are essential for a person's basic development (Obregón, 2008). The Mexicali – San Felipe highway was modernized as a  part of the main proposes in the National’s Infrastructure Plan 2007-2012 during Felipe Calderon Hinojosa’s presidential period, in which were prioritized construction and modernization projects with enough economic, financial and social profitability. The Mexicali – San Felipe section initiated the modernization process in 2006, assisting the communication needs between cities, ports, borders and touristic centers with high specification highways (SCT, 2011). The management procedure of the Mexicali – San Felipe project was done by the State and Federal Government to consolidate the North-South axis. This axis goes from Mexicali city, over the Golf of California’s littoral, passing through San Felipe and Puertecitos, and ends at the Transpeninsular Highway (Federal Highway No.1).

The majority of the economic activities from the secondary and the third sector can be located at Mexicali City; however the valley presents a significant agglomeration of agricultural production that gradually has been decreasing if compared to the rest of the activities developed in the metropolitan area (Zavala, 2006). The economic growth associated with agricultural production during the fifties and sixties changed during the seventies; during this period the economic growth was more associated to industrialization and services that continue being provided until today (García et al., 2011).

The present research shows how, during the partial modernization of the Federal Highway No. 5 Mexicali – San Felipe, was possible to improve the economic and social conditions of the population from 7 of the 10 localities with the higher amount of inhabitants and territorial area. To achieve this, the Urban Marginal Index was estimated ex – before (2000) and ex – post (2010) during the execution of the modernization process, according to the methodological logic used to guide investment decisions in the Ministry of Communications and Transportation (Secretaría de Comunicaciones y Transportes, SCT), in relation to what is established in the Federal Expenditure Budget (Presupuesto de Egresos Federales, PEF).

In addition, the second section will present the economic and social characteristics of the impacted area, followed by a review of literature about highways investments and its evaluation aspects. Therefore, an analysis methodology is used to generate the ex – before and ex – post evaluation results from the highway modernization project, achieving this through the Urban Marginal Index estimated for each locality at the minimal level of analysis. Finally, the conclusions show a debate and reflect about the impact caused by the partial growth of the highway in discussion and the welfare of the benefited communities.

Background

Mexicali County is the capital of Baja California, with a surface of 14 541 km²; it shares the border with Imperial Valley County, county located in California, United States  in Figure 1. Its main locality, carrying the same name, is head of a metropolitan area integrated by another 14 localities, from which only 10 require access through the Federal Highway No. 5 in Table 1. Population in this localities changed from 593 840 in 2000 to 774 957 in 2010 (INEGI, 2000; 2010).

The 10 localities geographic location, in relation to the Federal Highway No. 5, allows the establishment of three accessibility scenarios about the highway’s layout. Localities 1 and 3 are directly associated to the highway; localities 4, 5 and 6 are connected to the highway by a feeder road; and localities 2, 7, 8, 9, 10 are indirectly communicated with the highway through a secondary network. On its part, Federal Highway No. 5 Mexicali – San Felipe is integrated by three different subsections, the first one from the km 0+000 to km 38+000 (Mexicali – Algodones access), the second one from km 38+700 to km 170+400 (El Faro-El Chinero) and the third one from km 175+000 to km 190+000 (El Chinero – San Felipe) (Figure 1).

This area has a big influence over the touristic, agricultural, fishing, mining, commercial, services, and industrial sectors from Mexicali to San Felipe.  The route from kilometer 0+000 to 38+700 has accesses to Mexicali’s Valley. These accesses promote and facilitate economic activities in the suburban areas of the Valley. In “El Faro – El Chinero” section the Compañía San Felipe S.A. de C.V. is established, a mining company responsible for being the main source of employment in the area; meanwhile the “El Chinero – San Felipe” section is responsible for the development of tourism, fishing and commercial services (SCT, 2008a). This highway is one of the State’s axes with the potential to boost the touristic development and it is subject to modernization with the aim of improving accessibility and safety for users.

Mexicali’s county shows a diverse range of benefited activities, directly and indirectly, by the highway (Table 2). The retail trade business is the main activity with 8 594 units followed by temporary accommodation and food supply services with 2 426 units and manufacturing industry with 1 797 units (INEGI, 2012).

The first Urban Marginal Index (UMI) calculus made in Mexico was in 1990 for each federal entity and county (CONAPO, 2012). Its goal was to recognize the deficiencies in goods and services, as well as the quality of life from certain territories. The UMI is used to design public policies and programs, specifically to prevent and compensate the impacts caused by urban expansion processes over the public services planning (infrastructure, education, public and health services)(Ibidem).

Roads infrastructure evaluation takes into consideration diverse socioeconomic, environmental and technical studies based on an analysis methodology which allows one to understand its relevance from different points of view, whether it is social, administrative or legal; and from different scales (local, regional, national and international)  (SCT, 2011).  This  factors  are  included  in  the cost- benefit analysis and the road feasibility studies with an ex - before and ex – post perspective, taking into consideration scenarios before, during and after the project execution.

Ex-before projects evaluations are carried out in order to reduce the risk of the final decision. These evaluations allow one to visualize, in advance, the costs and benefits to estimate profitability indicators (MDS, 2013). Although projects of a social nature have been evaluated under ex-post criteria, nowadays they are evaluated with the ex-before criteria (SCT, 2008b).

Public administrations facilitate the cost-benefit analysis implementation as an appropriate tool for socioeconomic evaluation of road infrastructure investments. Even though this type of evaluation analysis has limitations, it tends to be very useful for decision-makers in the field (Barrios et al., 1997)

The ex-post evaluation is performed in order to check the effectiveness of the evaluation based on the experience, real values of the works, the immediate recognition of errors occurrence and the results effective disposal, regardless of the type. The analysis situations to be addressed are with and without project (MDS, 2013). This ex-post evaluation seeks to optimize the project operational efficiency and to estimate the changes that have occurred in the benefited population. This to evaluate the achievement level of the objectives set at the beginning. The difference between this two methods is focused on the benefits. The ex-before benefits occur in the future and the ex-post benefits occur during the course of the project (SCT, 2008b).

Building and modernize infrastructure is essential for any country’s public policies. Therefore it should be considered and evaluated if the investments, to which public funds will be destined, will generate economic profitability (Romero, 2001).

In recent years, a large number of developed countries have chosen good governance practices in terms of investments in transport infrastructure, based on ex-before and ex-post evaluations, and the  inclusion  of  economic – financial  plans  (Bel, 2009). The main conclusion is that the effects (economic activities, highway’s operational conditions, etc.) and the development inducted by the highway’s infrastructure bring solid benefits to the territory.

Investing in the quality of highway infrastructure is essential for the roads that cross a territory, their construction and maintenance.

These roads require a great financial and technological investment as well as a vast institutional and management capacity, since it stimulates the emergence and development of sectors such as the industrial, commercial, services, agriculture, among others; it encourages economic growth (Vassallo et al., 2010).

Population distribution is influenced by highways; the same happens with economic activities (Nogués et al., 2007). Due to its impact in transportation costs, accessibility is a significant factor. It facilitates the mobility of people and goods including those derived from the construction process, and as a result accessibility grants competitiveness to countries and regions (Papí et al., 2007).

Even though investments in road infrastructure do not stimulate on their own the local or regional development, the accessibility of a territory is vital and roads are the generating factor of such effect in rural and peripheral areas sparsely equipped with infrastructure (Nogués et al., 2007; Tarr et al., 1988).

The development of a territory is reason enough to justify a road construction project (SFP, 2011), since road networks develop an integrated roads system which adapts to the resulting effects from the space-temporality relations, choice of destinations, node selection, users accessibility, speed adaptation, etc., according to infrastructure changes that occur over time (Obregón, 2008; Dupuy, 1988).

The Urban Marginal Index (UMI) is used to assess changes in the quality of life due to the effects that the implementation of highway infrastructure has over it. To do so is used the ex-before and ex-post methodological context (SCT, 2008b), where the ex-before evaluation (before the project) primarily addresses the cost-benefit analysis, which measures the profitability of the project comparing the costs that may arise against the profits.

The ex-post evaluation (during and after project implementation) is better to assess projects with high social applications since it analyses their functionality, identifies trends or changes of the affected population and it determines the degree of efficiency achieved according to the desired objectives. This type of assessment allows one to evaluate the impact on the population even during the execution of the project, as in this case. In projects where the main goal is to measure the improvement in marginalization levels, the UMI is used as a goals inspector monitoring the success of each one of them and it allows the prioritization of study units for a subsequent territorial stratification. Furthermore this complies with a number of characteristics which demonstrate the homogeneity or heterogeneity, between the territorial divisions, by the minimum variance criteria (Bistrain, 2010). For this purpose, as a study unit the Basic Geostatistical Areas (BGA) are used which take into consideration urban and rural areas. This division is one of the 3 main territorial divisions based on the National Geostatistical Framework from the National Institute of Statistics and Geography better known as INEGI (CONAPO, 2012). The other two divisions are the Geostatistical State Area (GSA) and the Geostatistical Municipal Area (GMA).

As a part of the ex-before and ex-post evaluations, Urban Marginal Indexes were estimated in two periods, for BGA urban areas selected from Mexicali’s localities: the year 2000 as the ex-before and the year 2010 as the ex-post, taking as reference the modernization works from the Federal Highway No. 5 Mexicali – San Felipe, but only those registered at the Mexican Secretariat of Finance and Public Credit between 2006 and 2011 (SCT, 2008a) (Table 2).

As a consequence, the analysis of the ex-post situation considers the work accomplished during the execution until 2010 because in 2013 the work was not completed yet. For this purpose, the dimensions and socioeconomic indicators elected to estimate the UMI permit to measure the improvement in the quality of life of the benefited population in their respective areas, through the access to basic education, health and housing services (Table 3).

In order to determinate the UMI of the considered BGAs the marginalization level will be considered as medium high if the indicator value is between the average and one standard deviation, as high if it is between the average and two standard deviations and as very high if it is above two standard deviations. On the contrary the BGAs will have a medium low marginal level if the indicator value is between the average and minus one standard deviation, low if it is between the average and minus two standard deviations and very low if it is between the average and minus three standard deviations (Figure 2). For this purpose the Statistical Package for Social Science (SPSS) version 19.0 was used, the obtained results allow one to classify the urban marginalization level.

To obtain the index in the years 2000 and 2010, was considered data related to the educational situation: 1) 15+ years old inhabitants without education and/or with incomplete primary education; access to health services: 2) population without right to have health services; and housing situation: 3) housing with dirt floors, 4) housing without electricity, 5) housing without drainage system and 6) housing without water supply. The indicators selection was made estimating their improvement due to the highway modernization.

To calculate the UMI by the BGAs a procedure, that allows the weighted sum of each one of the indicators involved, was used (CONAPO, 2004):

IMi= Urban Marginal Index used by BGA

J  = Shows each one of the indicators (j = 1,…6).

aj= weight assigned to each marginalization indicator j (extracted from principal components matrix in SPSS)

Zij= standardized value of each marginalization indicator j, whose percentage is subtracted from the average value and y the difference is divided by the standard deviation from each socioeconomic indicator. ]  

Once obtained the summation of each socioeconomic indicator in its respective BGAs the marginalization level can be determined from the normal distribution in Figure 2. 

The location, of the 10 localities from the case study, has allowed us to establish three accessibility scenarios with regard to the highway, which are: a) directly related to its layout and design, b) communicated through a feeder road, and c) communicated indirectly through the secondary network.

The localities of Mexicali  and  San  Felipe,  situated  at the ends of the road, exemplify the localities directly related to this part of the Federal Highway No. 5. In both places most of the marginalization levels decreased, with significant improvements which reached low marginal levels in some BGAs. Mexicali City increased 15 times its BGAs quantity due to its population growth, meanwhile San Felipe only added 2 BGAs between one year and another. Likewise, Ejido Puebla, Colonia Progreso and Colonia  Carranza  localities  decreased  the  UMI  due to their interconnections with the highway through a feeder road.

Furthermore, 5 localities indirectly associated with the Federal Highway No. 5 Mexicali-San Felipe section through the secondary network show lower benefits during the modernization work. For the Michoacán de Ocampo and Nuevo Leon localities, urban marginal levels were the same despite their proximity to the capital and lower distance to the highway section. The Delta station had an increase of 1 BGA and a minimal improvement on its marginalization levels; Guadalupe Victoria had an improvement in almost all of its BGAs marginal levels, regardless of its limited access to the highway.

This leads to a hypothesis for future work, the Guadalupe Victoria enhancement is directly related to its better access to Federal Highway Mexicali – San Luis Rio Colorado through feeder roads. Finally, Ejido Coahuila is the only locality with higher levels of marginalization due to its difficult access to the highway.

As a result the benefits obtained during the modernization process can be associated to the accessibility conditions of each locality, to urban redistribution processes (evident with the emergence of new BGAs) and to the strengthening of the economic sectors directly associated with various sections of the highway (industry and agriculture in the first section, mining in the second and tourism and fishing in the third section). This seems even more determinant than the geographic distance between the localities and the road axis. However, it is important to note that for purposes of this research and in order to obtain the UMI levels the methodology used took into account only the modernization effects over variables related to a better quality of life, such as education, health services and housing, being the accessibility the main cause of the UMI improvement. Therefore, localities that worsened their marginalization levels between one year and another, are those with greater access problems. Future research should evaluate other types of public and private investments made due to the Federal Highway No. 5 Mexicali-San Felipe modernization and their effects over the accessibility benefits obtained.

The author has not declared any conflict of interests