Tipos de riesgos en el sistema financiero

Although ex-ante appraisal is frequently conducted for transport projects, ex-post evaluations are only carried out occasionally. However, ex-post evaluations can provide important insights in actual, and not estimated, project performance. These insights are useful to improve transport planning and transport system design. Current transport evaluation practice puts a distinct focus on economic appraisal, but often underrepresents or completely excludes social and environmental impacts. Furthermore, BRT systems’ popularity and implementation has increased, especially in Latin American countries, although many still regard MRT a superior alternative. However, arguments are often based on sentiments and personal preference and not on rational arguments. One of the reasons for this is that no studies exist that evaluate and compare the impacts of both systems. Therefore, impact comparison is only possible using various studies that apply different methodologies. In order to bridge this knowledge gap, the objective of this research was to develop and apply an ex-post evaluation framework to assess and compare the impacts of BRT and MRT systems in Mexico. The framework was tested in Mexico City, one of the few cities in which both a BRT and MRT system exists. The ex-post evaluation was conducted for the fourth Metrobús line and the twelfth Metro line, both of which started operation in 2012.

In order to develop an ex-post evaluation framework, a literature review on transport evaluation theories was conducted. Based on this literature review several choices for the evaluation framework were made. First of all, indicators were grouped according to the social, environmental and economic concepts of sustainable development. Secondly, only economic indicators were monetized, because otherwise social and environmental indicators are represented insufficiently in the outcomes. Third of all, if applicable, impacts were expressed in relative change to allow for comparison between the two transit lines. Fourthly, an egalitarian approach of indicator calculation was preferred to account for the large (income) inequalities in Mexico City. Finally, indicators were aggregated and evaluated using the flag model. This model uses impacts found in literature to evaluate the performance of the indicator. The outcomes of the evaluation are shown in Table 8-1.

The social indicators included in the framework are equity and safety. The results show that both transit lines effectuated a significant equity improvement, although the Metro line performs slightly better. Compared to other studies, this performance is good. Furthermore, the Gini- indices indicate that the travel time savings are distributed very equally over income groups. In terms of safety both lines show improvement and especially the Metro line. However, compared to other studies these safety improvements are low to medium. The safety improvements are mainly enjoyed by passengers, while indirect safety impacts are minimal.

The framework consists of three environmental indicators: air pollution, climate change and modal shift. Both air pollution and climate change emission reductions are observed for both lines, but these are higher for the Metro. However, these are lower than the emission reductions found in other studies. The emission reductions resulting from the Metro line have some impacts on total emissions in the MCMA, but for Metrobús these reductions are negligible on a city scale. The modal shift from private vehicles is highest for Metrobús. Compared to other studies, the

modal shift is high for Metrobús and low for Metro. Conversely, the Metro implementation results in a larger absolute modal shift, especially from low-capacity public transport.

Four economic indicators are part of the evaluation framework. Firstly, the Metro performs better in terms of travel time savings. Compared with values in other studies, both transit lines perform below the average. However, direct travel time savings are much higher and above the average. Secondly, construction costs are much lower for Metrobús. The construction costs of the Metrobús line are below the average construction costs of other mass transit systems, while the Metro construction costs are above the average. However, in comparison with other MRT systems the construction costs are lower than average. Thirdly, a similar trend is observed for the operating and maintenance costs, which are higher for the Metro and above the average of other studies. Meanwhile, Metrobús operating and maintenance costs are well below average. Finally, these operating and maintenance costs are more than compensated for by the revenues. For both transit lines, the revenues exceed the operating and maintenance costs, indicating operating profits. However, Metro revenues are much higher, also in comparison with other systems, while Metrobús revenues are low.

Aggregation of these indicators using the flag model shows that the Metrobús performs better for economic and environmental indicators, while the Metro has a higher social performance. Overall, the two transit lines are almost equal, although the Metrobús performs slightly better. Furthermore, standardized values indicate that both lines perform just under average compared to other studies. However, it is important to note that the framework more elaborately evaluates economic and environmental impacts than social impacts. In terms of economic profitability, the outcomes of the Metro strongly depend on the value of time. Meanwhile, the Metrobús is profitable in every VOT scenario. Additionally, the B/C ratio indicates that economically the Metrobús is more efficient. This is also confirmed by the economic efficiency of individual indicators. However, the efficiency per user trip, representing the impact of each passenger trip, is higher for Metro for environmental indicators. This shows that in order to reduce air pollution and climate change, the Metro system is more effective.

Metrobús Metro

Indicator Abbr. Indicator _value Standardized _value Indicator _value Standardized _value

Ec

on

om

ic

Travel time savings TTS 11.1% -2.00 21.7% -0.64

Construction costs CON $1,468,890 1.12 $65,853,454 -0.49

Operating & maintenance costs OM $178,380 2.00 $1,733,957 -2.00

Revenues RE $267,992 -1.34 $2,024,209 1.49 Economic EC - -0.05 - -0.41 So ci al Equity EQ 31.3% 2.00 39.8% 2.00 Safety SA 23.4% -0.86 29.6% -0.40 Social SO - 0.57 - 0.80 En vi ro nm en ta

l _{Air pollution POL -12.3% -1.47 -29.6% -0.53}

Climate change CC -4.9% -2.00 -22.8% -1.17

Modal shift MS 14.3% 1.10 7.5% -1.09

Environmental EN - -0.79 - -0.93

Overall OV - -0.09 - -0.18