There are many places to get gas, but to be on the safe side we fueled up just under a half tank. Pemex stations become very frequent the closer you get to Mexico City. Mexican highways are marked, but not like the US; there is generally little warning. These stations are full service--tips are expected by the attendant...we generally tipped 3-5% of the gas price.
Also, be prepared to pay anywhere from $3-5 pesos to use the bathrooms at the Pemex stations, make sure you carry a roll of TP--some "sanitarios/banos" (restrooms) do not have paper. AND remember not to flush the paper - their sewage system cannot break down the inorganic materials.
The highways and toll roads have businesses along both sides, exits and entrances are short, be constantly aware of on-coming vehicles. Random animals (cows, horses, goats, donkeys) and humans share the road too!
Toll booths (Caseta de Cobro) will only accept pesos! Check your change before pulling away from booth. Get your money changed before heading into Mexico!
Toll roads (Cuota) vary in speed limits from 80 KPH (50 MPH) to 110 KPH (70 MPH). Many Mexican drivers far exceed the speed limit and drive in the far left lane with their left turn signal on - meaning they want to pass (just like the Autobahn).
Mexican traffic lights blink green before turning yellow, then red. Ample warning!!
DO NOT DRIVE AT NIGHT!!! There are no street lights, undependable lane paint, and we understand it can become mortally dangerous!
We attempted to document accrued odometer mileage/kilometers, road signs, 11/2012 toll booth charges, restrooms, etc.
(10th St. intersects with 23rd St. just before border crossing.)
Toll at International Bridge, $3.00 USD
Once through the border, the Mexican checkpoint road bears right,
follow sign to Monterrey. Tricky through here - GPS is needed to get to Route 40D.
Follow signs to Route 40D. Note: Pemex on right, restrooms, no toilet
Mexican inspection station. Requested our vehicle permit, asked where
we were going. Neither passports nor tourist permits were requested.
"Caseta de Cobro" - Tollbooth, $210 pesos ($16.60USD)
Pemex station and Circle K on left, across the median.
Didn't stop, as we already utilized camping procedure to
relieve ourselves at one of the many trash bin pull-offs. Note: Not sure
if you can exit Pemex here and continue directly west, however if you are
forced to travel east, there are many places to legally pull a U-turn (Retorno).
Route 40D ends at Cadereyta, follow signs to the Saltillo Cuota. Your route will be on a frontage road, which was currently under construction. There are several Pemex stations, we stopped at the 1st one on the right, gassed up and used the restrooms.
Caseta de Cobro, $42pesos ($3.32USD) This is the northern loop around
Exit to Saltillo. Beautiful drive through the mountains coming up, after
you endure the insect assault on your windshield, the bovine slaughterhouse stench and other industrial pollutants.
Caseta de Cobro, $101pesos ($8.00USD) Most tollbooths have restrooms after
you pay, plus small eateries. Great places to stop and get some Mexican
fare. Typically we have found the roadside restaurants where buses and
truckers frequent are your best bet when you do not want to get off the
Caseta de Cobro, $130pesos ($10.27USD)
Caseta de Cobro, $45pesos ($3.55USD)
Follow signs to Matehuala
Route 57D to Matehuala
Caseta de Cobro, $55pesos ($4.35USD)
Spent the afternoon and night in Matehuala at the Las Palmas Hotel.