related" crashes claimed the lives of 179 people, which represents almost half (46.3%) of 387 autobahn fatalities that year. However, "excessive speed" does not mean that a speed limit has been exceeded, but that police determined at least one party travelled too fast for existing road or weather conditions. On autobahns 22 people died per 1,000 injury crashes, a lower rate than the 29 deaths per 1,000 injury accidents on conventional rural roads, which in turn is five times higher than the risk on urban roads—speeds are higher on rural roads and autobahns than urban roads, increasing the severity potential of a crash. Safety: international comparison A few countries publish the safety record of their motorways; the Federal Highway Research Institute provided IRTAD statistics for the year 2012: For example, a person yearly traversing on regular roads and on motorways has an approximately chance of dying in a car accident on a German road in any particular year ( on an autobahn), compared to in Czech Republic, in Denmark, or in the United States. However, there are many differences between countries in their geography, economy, traffic growth, highway system size, degree of urbanization and motorization, and so on. The European Union publishes statistics reported by its members. Travel speeds The federal government does not regularly measure or estimate travel speeds. One study reported in a transportation engineering journal offered historical perspective on the increase in travel speeds over a decade: Source: Kellermann, G: Geschwindigkeitsverhalten im Autobahnnetz 1992. Straße+Autobahn, Issue 5/1995. The Federal Environmental Office reported that, on a free-flowing section in 1992, the recorded average speed was with 51% of drivers exceeding the recommended speed. In 2006, speeds were recorded using automated detection loops in the State of Brandenburg at two points: on a six-lane section of A 9 near Niemegk with a advisory speed limit; and on a four-lane section of A 10 bypassing Berlin near Groß Kreutz with a mandatory limit. The results were: At peak times on the "free-flowing" section of A 9, over 60% of road users exceeded the recommended maximum speed, more than 30% of motorists exceeded , and more than 15% exceeded —in other words the so-called "85th-percentile speed" was in excess of 170 km/h. Toll roads On 1 January 2005, a new system came into effect for mandatory tolls (Mautpflicht) on heavy trucks (those weighing more than 12 t) while using the German