How to internalize congestion costs through a pricing scheme in the metropolitan area of madrid

Following the EU policy oriented to implement a tolling system based on social marginal costs, Spain is studying the implementation of an interurban road pricing scheme. In particular, a main result from the Spanish Road Pricing Model suggests that a road pricing scheme based on the congestion costs makes sense only in the reduced number of metropolitan highways and can be used to manage the travel demand in an urban and metropolitan context. In consequence, the analysis of this paper is focused on the results of the simulation of a toll-ring defined as a combined toll (access and distance toll based scheme) applied on the one of the more congested ring of the Madrid Metropolitan Area, the M40. The results are analyzed in terms of efficiency and equity criteria. Finally, the results of the implementation of a toll-ring pricing policy show a clear increasing level of socio-spatial inequalities. In fact, when the users have a viable road alternative, the burden of the toll-ring is equally distributed, if not, the burden of toll ring affects more the less wealthy people

Environmental Costs Account: a base for measuring sustainability in transport plans.

Each city need to develop sustainable transport plans according to its fu-ture developments. This means identifying the best policy package of transport measures that could produce more sustainable future scenarios: lowest environmental impact, but also better social standards and at mini-mum cost. To that end, it is necessary to measure the environmental and social costs of each alternative transport mode. This paper proposes a me-thodology to calculate those costs in different city contexts: city centre and metropolitan suburbs. It provides a measure of the following environmen-tal costs: pollution, noise, green house gasses and land taken. Then the so-cial costs as congestion and accident costs. These two cost categories are calculated for each mean of transport: metro, bus, private car and taxi. The methodology has been applied to Madrid Region through modeling its mobility demand in 2004. The outputs are costs per passenger-km in each mode and Area: city centre and metropolitan ring. Therefore it is possible to assign monetary costs to environmental and social costs of each trans-port option; for example, car environmental costs are four times higher than buses on average, but it differs a lot from city centre to outskirt areas. Finally, some guidelines can be extracted to develop a more sustainable transport policy for Madrid Region

Deconstructing double-barred galaxies in 2D and 3D. II. Two distinct groups of inner bars

The intrinsic photometric properties of inner and outer stellar bars within 17 double-barred galaxies are thoroughly studied through a photometric analysis consisting of: i) two-dimensional multi-component photometric decompositions, and ii) three-dimensional statistical deprojections for measuring the thickening of bars, thus retrieving their 3D shape. The results are compared with previous measurements obtained with the widely used analysis of integrated light. Large-scale bars in single- and double-barred systems show similar sizes, and inner bars may be longer than outer bars in different galaxies. We find two distinct groups of inner bars attending to their in-plane length and ellipticity, resulting in a bimodal behaviour for the inner/outer bar length ratio. Such bimodality is related neither to the properties of the host galaxy nor the dominant bulge, and it does not show a counterpart in the dimension off the disc plane. The group of long inner bars lays at the lower end of the outer bar length vs. ellipticity correlation, whereas the short inner bars are out of that relation. We suggest that this behaviour could be due to either a different nature of the inner discs from which the inner bars are dynamically formed, or a different assembly stage for the inner bars. This last possibility would imply that the dynamical assembly of inner bars is a slow process taking several Gyr to happen. We have also explored whether all large-scale bars are prone to develop an inner bar at some stage of their lives, possibility we cannot fully confirm or discard.Comment: 14 pages, 8 figures, 1 table. Accepted for publication in MNRA

Orthogonal vertical velocity dispersion distributions produced by bars

In barred galaxies, the contours of stellar velocity dispersions ($\sigma$) are generally expected to be oval and aligned with the orientation of bars. However, many double-barred (S2B) galaxies exhibit distinct $\sigma$ peaks on the minor axis of inner bars, which we termed "$\sigma$-humps," while two local $\sigma$ minima are present close to the ends of inner bars, i.e., "$\sigma$-hollows." Analysis of numerical simulations shows that $\sigma_z$-humps or hollows should play an important role in generating the observed $\sigma$-humps+hollows in low-inclination galaxies. In order to systematically investigate the properties of $\sigma_z$ in barred galaxies, we apply the vertical Jeans equation to a group of well-designed three-dimensional bar+disk(+bulge) models. A vertically thin bar can lower $\sigma_z$ along the bar and enhance it perpendicular to the bar, thus generating $\sigma_z$-humps+hollows. Such a result suggests that $\sigma_z$-humps+hollows can be generated by the purely dynamical response of stars in the presence of a, sufficiently massive, vertically thin bar, even without an outer bar. Using self-consistent $N$-body simulations, we verify the existence of vertically thin bars in the nuclear-barred and S2B models which generate prominent $\sigma$-humps+hollows. Thus the ubiquitous presence of $\sigma$-humps+hollows in S2Bs implies that inner bars are vertically thin. The addition of a bulge makes the $\sigma_z$-humps more ambiguous and thus tends to somewhat hide the $\sigma_z$-humps+hollows. We show that $\sigma_z$ may be used as a kinematic diagnostic of stellar components that have different thickness, providing a direct perspective on the morphology and thickness of nearly face-on bars and bulges with integral field unit spectroscopy.Comment: 14 pages, 16 figures. Accepted for publication in Ap